{"cik":916076,"taxonomy":"us-gaap","tag":"LongTermInvestments","label":"Long-term Investments","description":"The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).","entityName":"MARTIN MARIETTA MATERIALS INC","units":{"USD":[{"end":"2013-09-30","val":10094000,"accn":"0001193125-14-393639","fy":2014,"fp":"Q3","form":"10-Q","filed":"2014-11-03","frame":"CY2013Q3I"},{"end":"2013-12-31","val":9785000,"accn":"0001193125-14-393639","fy":2014,"fp":"Q3","form":"10-Q","filed":"2014-11-03","frame":"CY2013Q4I"},{"end":"2014-09-30","val":63766000,"accn":"0001193125-14-393639","fy":2014,"fp":"Q3","form":"10-Q","filed":"2014-11-03","frame":"CY2014Q3I"}]}}