Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Adjustments to net income (in dollars)	$ 0	$ 0	$ 0	$ 0
Antidilutive securities (in shares)	0	0	0	0
Numerator:
Net income	$ 72,433	$ 69,053	$ 142,357	$ 137,011
Denominator:
Basic: weighted-average shares outstanding (in shares)	134,420,380	137,907,063	134,655,217	138,749,209
Add: weighted-average equity-based awards (in shares)	231,628	158,816	269,114	142,746
Diluted: weighted-average shares outstanding (in shares)	134,652,008	138,065,879	134,924,331	138,891,955
Basic earnings per share (in dollars per share)	$ 0.54	$ 0.50	$ 1.06	$ 0.99
Diluted earnings per share (in dollars per share)	$ 0.54	$ 0.50	$ 1.06	$ 0.99

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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