Supplementary Quarterly Financial Data (Unaudited) - (Tables)

12 Months Ended

Dec. 31, 2018

Quarterly Financial Information Disclosure [Abstract]

Schedule of Supplementary Quarterly Financial Data

SUPPLEMENTARY QUARTERLY FINANCIAL DATA (UNAUDITED)

	For the Three Months Ended
	March 31, 2018		June 30, 2018		September 30, 2018		December 31, 2018
Revenues	$	285,485	$	296,813	$	306,953	$	307,353
Cost of operations	151,573		152,097		153,362		150,676
Revenues less cost of operations	$	133,912	$	144,716	$	153,591	$	156,677
Net income	$	95,430	$	102,713	$	139,687	$	109,250
Net income attributable to common stockholders	$	88,256	$	95,153	$	130,418	$	101,462
Earnings per common share—basic	$	0.70	$	0.75	$	1.03	$	0.80
Earnings per common share—diluted	$	0.70	$	0.75	$	1.02	$	0.80
	For the Three Months Ended
	March 31, 2017		June 30, 2017		September 30, 2017		December 31, 2017
Revenues	$	263,008	$	276,003	$	284,156	$	281,842
Cost of operations	138,805		139,596		144,275		140,728
Revenues less cost of operations	$	124,203	$	136,407	$	139,881	$	141,114
Net income	$	89,734	$	94,098	$	101,075	$	229,315
Net income attributable to common stockholders	$	82,282	$	87,006	$	93,742	$	215,983
Earnings per common share—basic	$	0.65	$	0.69	$	0.74	$	1.71
Earnings per common share—diluted	$	0.64	$	0.69	$	0.74	$	1.69