Acquisitions - Unaudited Supplemental Pro Forma Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Combinations [Abstract]
Revenues	$ 2,506,231	$ 2,996,243	$ 5,273,181	$ 5,964,481
Gross profit	355,264	351,820	688,666	748,918
Selling, general and administrative expenses	227,852	235,433	458,954	479,288
Amortization of intangible assets	17,779	18,798	35,845	37,858
Net income	74,795	36,875	116,799	166,291
Net income attributable to common stock	$ 73,946	$ 35,760	$ 113,133	$ 164,629
Earnings per share:
Basic (in dollars per share)	$ 0.53	$ 0.24	$ 0.80	$ 1.13
Diluted (in dollars per share)	$ 0.52	$ 0.24	$ 0.78	$ 1.12