Description of Business and Significant Accounting Policies Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Research and Development [Abstract]
Cash and Cash Equivalents	$ 447	$ 338	$ 509
Restricted Cash included in other assets	7	9	7
Funds Held for Clients included in other current assets	48	44	32
Cash included in settlement processing assets included in other current assets	247	15	15
Cash, Cash Equivalents, Restricted Cash at end of period	$ 749	$ 406	$ 563