Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 493,951	$ (237,488)
Effective income tax rate, percent	20.72%	22.44%
Federal Statutory income tax rate, percent	21.00%