Fair Value Measurements - Distribution of Financial Instruments, Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions | Mar. 31, 2020 | Dec. 31, 2019 |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Deferred compensation assets | $ 53 | $ 67 |
Foreign exchange derivative liabilities | (20) | (32) |
Deferred compensation liabilities | (60) | (67) |
Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Deferred compensation assets | 53 | 67 |
Foreign exchange derivative liabilities | 0 | 0 |
Deferred compensation liabilities | (60) | (67) |
Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Deferred compensation assets | 0 | 0 |
Foreign exchange derivative liabilities | (20) | (32) |
Deferred compensation liabilities | 0 | 0 |
Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Deferred compensation assets | 0 | 0 |
Foreign exchange derivative liabilities | 0 | 0 |
Deferred compensation liabilities | 0 | 0 |
Municipal securities | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 18 | 15 |
Municipal securities | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Municipal securities | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 18 | 15 |
Municipal securities | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Government and agency securities | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 18 | 108 |
Government and agency securities | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 66 |
Government and agency securities | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 18 | 42 |
Government and agency securities | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Corporate securities | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 310 | 382 |
Corporate securities | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Corporate securities | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 310 | 382 |
Corporate securities | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Asset-backed securities | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 68 | 86 |
Asset-backed securities | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Asset-backed securities | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 68 | 86 |
Asset-backed securities | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Equity securities | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 282 | 479 |
Equity securities | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 282 | 479 |
Equity securities | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Equity securities | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Investment securities available for sale | 0 | 0 |
Foreign exchange contracts | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 87 | 12 |
Foreign exchange contracts | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 0 | 0 |
Foreign exchange contracts | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 87 | 12 |
Foreign exchange contracts | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 0 | 0 |
Interest rate contracts | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 0 | 14 |
Interest rate contracts | Fair Value, Inputs, Level 1 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 0 | 0 |
Interest rate contracts | Fair Value, Inputs, Level 2 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | 0 | 14 |
Interest rate contracts | Fair Value, Inputs, Level 3 | | |
Fair Value, Option, Quantitative Disclosures [Line Items] | | |
Derivative instrument | $ 0 | $ 0 |