Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive stock options whose exercise prices were higher than the common stock's average market price during the period (in shares)									64	34	1
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic									$ (2,771,000)	$ (4,151,000)	$ (4,321,000)
Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights									207	221	268
Net income	$ 51,437,000	$ 137,843,000	$ 232,250,000	$ 101,699,000	$ 71,863,000	$ 190,055,000	$ 307,283,000	$ 179,261,000	$ 523,229,000	$ 748,462,000	$ 650,624,000
Net Income (Loss) Available to Common Stockholders, Basic									$ 520,458,000	$ 744,311,000	$ 646,303,000
Weighted average shares outstanding [Abstract]
Basic (in shares)									38,704	39,409	39,876
Effect of dilutive securities [Abstract]
Stock options and employee stock purchase plan (in shares)									293	397	604
Diluted (in shares)									38,997	39,806	40,480
Basic (in dollars per share)	$ 1.33	$ 3.54	$ 5.95	$ 2.60	$ 1.84	$ 4.82	$ 7.71	$ 4.46	$ 13.45	$ 18.89	$ 16.21
Diluted (in dollars per share)	$ 1.32	$ 3.51	$ 5.91	$ 2.58	$ 1.82	$ 4.78	$ 7.63	$ 4.41	$ 13.35	$ 18.70	$ 15.97
Anti-dilutive stock options whose exercise prices were higher than the common stock's average market price during the period (in shares)									64	34	1