{"cik":1057352,"taxonomy":"us-gaap","tag":"LongTermDebt","label":"Long-term Debt","description":"Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.","entityName":"COSTAR GROUP, INC.","units":{"USD":[{"end":"2012-06-30","val":172813000,"accn":"0001057352-12-000117","fy":2012,"fp":"Q2","form":"10-Q","filed":"2012-07-26","frame":"CY2012Q2I"},{"end":"2012-09-30","val":170625000,"accn":"0001057352-12-000158","fy":2012,"fp":"Q3","form":"10-Q","filed":"2012-10-25","frame":"CY2012Q3I"},{"end":"2012-12-31","val":170625000,"accn":"0001057352-13-000013","fy":2012,"fp":"FY","form":"10-K","filed":"2013-03-01","frame":"CY2012Q4I"},{"end":"2013-12-31","val":153125000,"accn":"0001057352-14-000006","fy":2013,"fp":"FY","form":"10-K","filed":"2014-02-20","frame":"CY2013Q4I"},{"end":"2014-12-31","val":385000000,"accn":"0001057352-15-000012","fy":2014,"fp":"FY","form":"10-K","filed":"2015-02-26"},{"end":"2014-12-31","val":371801000,"accn":"0001057352-16-000103","fy":2015,"fp":"FY","form":"10-K","filed":"2016-02-26","frame":"CY2014Q4I"},{"end":"2015-12-31","val":355112000,"accn":"0001057352-16-000103","fy":2015,"fp":"FY","form":"10-K","filed":"2016-02-26"},{"end":"2015-12-31","val":355112000,"accn":"0001057352-16-000128","fy":2016,"fp":"Q1","form":"10-Q","filed":"2016-04-28"},{"end":"2015-12-31","val":355112000,"accn":"0001057352-16-000143","fy":2016,"fp":"Q2","form":"10-Q","filed":"2016-07-28"},{"end":"2015-12-31","val":355112000,"accn":"0001057352-16-000165","fy":2016,"fp":"Q3","form":"10-Q","filed":"2016-10-27"},{"end":"2015-12-31","val":355112000,"accn":"0001057352-17-000008","fy":2016,"fp":"FY","form":"10-K","filed":"2017-02-24","frame":"CY2015Q4I"},{"end":"2016-03-31","val":350923000,"accn":"0001057352-16-000128","fy":2016,"fp":"Q1","form":"10-Q","filed":"2016-04-28","frame":"CY2016Q1I"},{"end":"2016-06-30","val":336722000,"accn":"0001057352-16-000143","fy":2016,"fp":"Q2","form":"10-Q","filed":"2016-07-28","frame":"CY2016Q2I"},{"end":"2016-09-30","val":337519000,"accn":"0001057352-16-000165","fy":2016,"fp":"Q3","form":"10-Q","filed":"2016-10-27","frame":"CY2016Q3I"},{"end":"2016-12-31","val":338339000,"accn":"0001057352-17-000008","fy":2016,"fp":"FY","form":"10-K","filed":"2017-02-24"},{"end":"2016-12-31","val":338339000,"accn":"0001057352-17-000027","fy":2017,"fp":"Q1","form":"10-Q","filed":"2017-04-27"},{"end":"2016-12-31","val":338339000,"accn":"0001057352-17-000045","fy":2017,"fp":"Q2","form":"10-Q","filed":"2017-07-27"},{"end":"2016-12-31","val":338339000,"accn":"0001057352-17-000075","fy":2017,"fp":"Q3","form":"10-Q","filed":"2017-10-26"},{"end":"2016-12-31","val":338339000,"accn":"0001057352-18-000011","fy":2017,"fp":"FY","form":"10-K","filed":"2018-02-23","frame":"CY2016Q4I"},{"end":"2017-03-31","val":304111000,"accn":"0001057352-17-000027","fy":2017,"fp":"Q1","form":"10-Q","filed":"2017-04-27","frame":"CY2017Q1I"},{"end":"2017-06-30","val":304826000,"accn":"0001057352-17-000045","fy":2017,"fp":"Q2","form":"10-Q","filed":"2017-07-27","frame":"CY2017Q2I"},{"end":"2017-09-30","val":305496000,"accn":"0001057352-17-000075","fy":2017,"fp":"Q3","form":"10-Q","filed":"2017-10-26","frame":"CY2017Q3I"},{"end":"2017-12-31","val":0,"accn":"0001057352-19-000017","fy":2018,"fp":"FY","form":"10-K","filed":"2019-02-28","frame":"CY2017Q4I"},{"end":"2018-12-31","val":0,"accn":"0001057352-19-000052","fy":2019,"fp":"Q1","form":"10-Q","filed":"2019-04-24"},{"end":"2018-12-31","val":0,"accn":"0001057352-19-000094","fy":2019,"fp":"Q3","form":"10-Q","filed":"2019-10-23"},{"end":"2018-12-31","val":0,"accn":"0001057352-20-000036","fy":2019,"fp":"FY","form":"10-K","filed":"2020-02-26","frame":"CY2018Q4I"},{"end":"2019-06-30","val":0,"accn":"0001057352-19-000065","fy":2019,"fp":"Q2","form":"10-Q","filed":"2019-07-24","frame":"CY2019Q2I"},{"end":"2019-12-31","val":0,"accn":"0001057352-20-000036","fy":2019,"fp":"FY","form":"10-K","filed":"2020-02-26","frame":"CY2019Q4I"},{"end":"2020-09-30","val":1000000000,"accn":"0001057352-20-000126","fy":2020,"fp":"Q3","form":"10-Q","filed":"2020-10-28","frame":"CY2020Q3I"},{"end":"2020-12-31","val":1000000000,"accn":"0001057352-21-000032","fy":2020,"fp":"FY","form":"10-K","filed":"2021-02-24","frame":"CY2020Q4I"},{"end":"2021-03-31","val":1000000000,"accn":"0001057352-21-000067","fy":2021,"fp":"Q1","form":"10-Q","filed":"2021-04-28","frame":"CY2021Q1I"},{"end":"2021-06-30","val":1000000000,"accn":"0001057352-21-000082","fy":2021,"fp":"Q2","form":"10-Q","filed":"2021-07-28","frame":"CY2021Q2I"},{"end":"2021-09-30","val":1000000000,"accn":"0001057352-21-000104","fy":2021,"fp":"Q3","form":"10-Q","filed":"2021-10-27","frame":"CY2021Q3I"},{"end":"2021-12-31","val":1000000000,"accn":"0001057352-22-000027","fy":2021,"fp":"FY","form":"10-K","filed":"2022-02-23","frame":"CY2021Q4I"},{"end":"2022-03-31","val":1000000000,"accn":"0001057352-22-000054","fy":2022,"fp":"Q1","form":"10-Q","filed":"2022-04-28","frame":"CY2022Q1I"},{"end":"2022-06-30","val":1000000000,"accn":"0001057352-22-000084","fy":2022,"fp":"Q2","form":"10-Q","filed":"2022-07-27","frame":"CY2022Q2I"},{"end":"2022-09-30","val":1000000000,"accn":"0001057352-22-000121","fy":2022,"fp":"Q3","form":"10-Q","filed":"2022-10-26","frame":"CY2022Q3I"},{"end":"2022-12-31","val":1000000000,"accn":"0001057352-23-000030","fy":2022,"fp":"FY","form":"10-K","filed":"2023-02-22","frame":"CY2022Q4I"},{"end":"2023-03-31","val":1000000000,"accn":"0001057352-23-000075","fy":2023,"fp":"Q1","form":"10-Q","filed":"2023-04-26","frame":"CY2023Q1I"},{"end":"2023-06-30","val":1000000000,"accn":"0001057352-23-000111","fy":2023,"fp":"Q2","form":"10-Q","filed":"2023-07-26","frame":"CY2023Q2I"},{"end":"2023-09-30","val":1000000000,"accn":"0001057352-23-000127","fy":2023,"fp":"Q3","form":"10-Q","filed":"2023-10-25","frame":"CY2023Q3I"},{"end":"2023-12-31","val":1000000000,"accn":"0001057352-24-000013","fy":2023,"fp":"FY","form":"10-K","filed":"2024-02-22","frame":"CY2023Q4I"},{"end":"2024-03-31","val":1000000000,"accn":"0001057352-24-000059","fy":2024,"fp":"Q1","form":"10-Q","filed":"2024-04-24","frame":"CY2024Q1I"},{"end":"2024-06-30","val":1000000000,"accn":"0001057352-24-000091","fy":2024,"fp":"Q2","form":"10-Q","filed":"2024-07-25","frame":"CY2024Q2I"},{"end":"2024-09-30","val":1000000000,"accn":"0001057352-24-000125","fy":2024,"fp":"Q3","form":"10-Q","filed":"2024-10-23","frame":"CY2024Q3I"},{"end":"2024-12-31","val":1000000000,"accn":"0001057352-25-000016","fy":2024,"fp":"FY","form":"10-K","filed":"2025-02-20","frame":"CY2024Q4I"},{"end":"2025-03-31","val":1000000000,"accn":"0001057352-25-000067","fy":2025,"fp":"Q1","form":"10-Q","filed":"2025-05-01","frame":"CY2025Q1I"},{"end":"2025-06-30","val":1000000000,"accn":"0001057352-25-000097","fy":2025,"fp":"Q2","form":"10-Q","filed":"2025-07-23","frame":"CY2025Q2I"},{"end":"2025-09-30","val":1000000000,"accn":"0001057352-25-000120","fy":2025,"fp":"Q3","form":"10-Q","filed":"2025-10-29","frame":"CY2025Q3I"},{"end":"2025-12-31","val":140000000,"accn":"0001057352-26-000020","fy":2025,"fp":"FY","form":"10-K","filed":"2026-02-26","frame":"CY2025Q4I"},{"end":"2026-03-31","val":1000000000,"accn":"0001057352-26-000035","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-04-29","frame":"CY2026Q1I"},{"end":"2026-06-30","val":1000000000,"accn":"0001057352-26-000066","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-07-29","frame":"CY2026Q2I"}]}}