Fair Value Measurements and Fair Value of Financial Instruments Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($) $ in Millions |
12 Months Ended | |
---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Asset (Liability), Gain (Loss), Statement of Income [Extensible List] | us-gaap:SellingGeneralAndAdministrativeExpense | |
Contingent Consideration [Member] | ||
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||
Balance at Beginning of Year | $ 55 | $ 37 |
Acquisitions (including assumed balances) | 28 | 24 |
Payments | (4) | (3) |
Changes in fair value included in earnings | (9) | (3) |
Balance at End of Year | $ 70 | $ 55 |