Earnings Per Share of Common Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Diluted earnings per share of common stock:
Net income attributable to common stockholders	$ 204,229	$ 352,677	$ 581,097	$ 658,920
Weighted-average common stock outstanding applicable to basic earnings per share (in shares)	65,890	77,790	67,493	78,240
Effect of dilutive shares:
Common shares issuable under stock-based compensation plans (in shares)	3,509	2,634	3,755	3,001
Weighted-average shares of common stock applicable to diluted earnings per share (in shares)	69,399	80,424	71,248	81,241
Basic earnings per share of common stock (in dollars per share)	$ 3.10	$ 4.53	$ 8.61	$ 8.42
Diluted earnings per share of common stock (in dollars per share)	$ 2.94	$ 4.39	$ 8.16	$ 8.11
Total anti-dilutive shares and units (in shares)	557	774	388	591
Performance-based RSUs
Effect of dilutive shares:
Total anti-dilutive shares and units (in shares)	308	422	215	292
Time-based RSUs
Effect of dilutive shares:
Total anti-dilutive shares and units (in shares)		79		110
Stock Options
Effect of dilutive shares:
Total anti-dilutive shares and units (in shares)	249	273	173	189
Weighted-average exercise price of anti-dilutive stock options (in dollars per share)	$ 58.85	$ 35.03	$ 58.85	$ 35.03