Earnings Per Share Level 4 (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2020		Sep. 30, 2020		Jun. 30, 2020		Mar. 31, 2020		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Income (Loss) Attributable to Parent [Abstract]
Net income attributable to common stockholders	$ 201,043		$ 127,415		$ 105,508		$ 81,941		$ 147,152		$ 70,792		$ 72,329		$ 79,323		$ 515,907	$ 369,596	$ 447,208
Weighted average shares (denominator):
Weighted average shares — basic																	176,709	182,246	182,447
Weighted average shares — diluted																	178,990	185,523	186,972
Net income attributable to common stockholders, basic	$ 1.17	[1]	$ 0.72	[1]	$ 0.59	[1]	$ 0.45	[1]	$ 0.81	[1]	$ 0.39	[1]	$ 0.40	[1]	$ 0.44	[1]	$ 2.92	$ 2.03	$ 2.45
Net income attributable to common stockholders, diluted	$ 1.15	[1]	$ 0.72	[1]	$ 0.59	[1]	$ 0.45	[1]	$ 0.79	[1]	$ 0.38	[1]	$ 0.39	[1]	$ 0.43	[1]	$ 2.88	$ 1.99	$ 2.39
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																	1,614,000	678,000	1,035,000
Stock Options [Member]
Weighted average shares (denominator):
Share based compensation																	2,234	3,223	4,339
Restricted Stock Units (RSUs) [Member]
Weighted average shares (denominator):
Share based compensation																	47	54	186

[1] Net income per share is computed independently for each of the quarters presented. Therefore, the sum of the quarters’ net income per share may not equal the total computed for the year.