Per Share Information - Basic and Diluted Earnings Per Share Attributable to Common Stock (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Amounts attributable to common stock:
Net income attributable to common stock, basic	$ 117,033	$ 73,946	$ 206,794	$ 112,632
Net income attributable to common stock, diluted	$ 117,033	$ 73,946	$ 206,794	$ 112,632
Weighted average shares outstanding:
Weighted average shares outstanding for basic earnings per share attributable to common stock (in shares)	140,276,000	139,856,000	140,199,000	142,154,000
Effect of dilutive unvested non-participating stock-based awards (in shares)	4,331,000	3,665,000	4,324,000	3,059,000
Weighted average shares outstanding for diluted earnings per share attributable to common stock (in shares)	144,607,000	143,521,000	144,523,000	145,213,000