Quarterly Financial Information (Unaudited) - Quarterly Financial Data (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
Selected Quarterly Financial Information [Abstract]
Revenues	$ 446,285	$ 379,787	$ 407,719	$ 370,775	$ 360,565	$ 292,249	$ 333,934	$ 288,370	$ 1,604,566	$ 1,275,118	$ 1,184,719
Depreciation and amortization	53,287	53,998	53,553	53,009	31,221	30,994	29,995	28,666	213,847	120,876	111,959
Total operating income	71,748	56,503	85,316	53,964	51,526	40,100	76,699	45,944	267,531	214,269	185,917
Income before income taxes	43,182	24,427	54,516	24,644	161,191	24,454	61,222	29,548	146,769	276,415	126,945
Income before income taxes	(4,732)	(3,537)	(8,232)	(1,974)	(1,997)	(1,863)	(5,676)	(2,209)	(18,475)	(11,745)	49,155
Net income	38,450	20,890	46,284	22,670	159,194	22,591	55,546	27,339	128,294	264,670	176,100
Net income available to common shareholders	$ 44,654	$ 22,349	$ 49,383	$ 29,408	$ 159,194	$ 22,591	$ 55,546	$ 27,339	$ 145,794	$ 264,670	$ 176,100
Basic income per share available to common stockholders	$ 0.86	$ 0.43	$ 0.96	$ 0.57	$ 3.10	$ 0.44	$ 1.08	$ 0.53	$ 2.82	$ 5.16	$ 3.44
Diluted income per share available to common stockholders	$ 0.85	$ 0.43	$ 0.95	$ 0.57	$ 3.09	$ 0.44	$ 1.08	$ 0.53	$ 2.81	$ 5.14	$ 3.43