Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings per Share
Adjustments to net income (in dollars)	$ 0	$ 0
Antidilutive securities (in shares)	0	0
Numerator:
Net income	$ 69,924	$ 67,958
Denominator:
Basic: weighted-average shares outstanding (in shares)	134,879,336	139,600,712
Add: weighted-average equity-based awards (in shares)	319,009	131,388
Diluted: weighted-average shares outstanding (in shares)	135,198,345	139,732,100
Basic earnings per share (in dollars per share)	$ 0.52	$ 0.49
Diluted earnings per share (in dollars per share)	$ 0.52	$ 0.49