Basis of Presentation (Earnings per share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income	$ 304,107	$ 203,711
Less: earnings distributed to participating securities	(298)	(273)
Less: undistributed earnings allocated to participating securities	(2,154)	(1,537)
Numerator for basic earnings per share	301,655	201,901
Add back: undistributed earnings allocated to participating securities	2,154	1,537
Less: undistributed earnings reallocated to participating securities	(2,149)	(1,530)
Numerator for diluted earnings per share	$ 301,660	$ 201,908
Denominator:
Basic shares outstanding (shares)	265,407	270,000
Effect of dilutive securities (shares)	605	1,218
Diluted shares outstanding (shares)	266,012	271,218
Earnings per share:
Basic earnings (usd per share)	$ 1.14	$ 0.75
Diluted earnings (usd per share)	$ 1.13	$ 0.74