Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax expense	$ 281	$ 166	$ 497	$ 195
Unrecognized Tax Benefits	$ 333		$ 333		$ 298