Bluegrass Acquisition - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Combinations [Line Items]
Business acquisition in cash					$ 1,640,698
Total Revenues		$ 1,420,246	$ 1,219,640	$ 3,638,668	3,224,047
Earnings (Loss) from operations		345,263	240,662	700,365	543,696
Bluegrass Materials Company
Business Combinations [Line Items]
Business acquisition in cash	$ 1,620,000
Total Revenues		79,500	68,700	202,700	115,000
Earnings (Loss) from operations		$ 31,100	$ 11,500	$ 60,600	$ 18,300