Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 1,399,134	$ 1,401,638	$ 1,409,409	$ 1,191,335	$ 879,112	$ 909,781	$ 856,396	$ 765,439	$ 5,401,516	$ 3,410,728	$ 2,443,066
Operating income	59,531	18,405	48,621	21,423	20,408	4,894	28,983	27,656	147,980	81,941	93,961
Net income (loss)	$ 35,439	$ (83,891)	$ 28,169	$ 61,092	$ 13,886	$ (5,822)	$ 16,178	$ 15,185	$ 40,809	$ 39,427	$ 72,621
Net income (loss) per share
Basic (USD per share)	$ 0.68	$ (1.65)	$ 0.56	$ 1.23	$ 0.30	$ (0.13)	$ 0.35	$ 0.33	$ 0.80	$ 0.85	$ 1.58
Diluted (USD per share)	$ 0.68	$ (1.65)	$ 0.56	$ 1.14	$ 0.30	$ (0.13)	$ 0.35	$ 0.33	$ 0.80	$ 0.85	$ 1.57