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Employee Benefits - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Value of stock issued | $ 111 | $ 100 | $ 90
Matching contribution expense | $ 166 | 144 | 110
2004 Plan | Common Stock |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Common stock authorized (in shares) | 309 |  |
Shares available for future grant (in shares) | 82 |  |
2018 Plan | Common Stock |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Common stock authorized (in shares) | 12 |  |
Immunomedics Plan | Common Stock |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Common stock authorized (in shares) | 26 |  |
Stock option |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Expiration period | 10 years |  |
Intrinsic value of options exercised | $ 48 | $ 179 | $ 209
Weighted average grant date fair value (in dollars per share) | $ 10.05 | $ 11.69 | $ 12.15
Unrecognized compensation cost | $ 47 |  |
Period for recognition | 2 years 3 months 18 days |  |
Stock option | Minimum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Stock options vesting period | 3 years |  |
Stock option | Maximum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Stock options vesting period | 4 years |  |
RSUs |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Granted (in dollars per share) | $ 65.42 | 70.94 | 64.31
RSUs | Minimum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Stock options vesting period | 3 years |  |
RSUs | Maximum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Stock options vesting period | 4 years |  |
PSUs |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Granted (in dollars per share) | $ 71.31 | $ 83.64 | $ 68.30
PSUs | Minimum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Stock options vesting period | 1 year |  |
Payout percentage | 0.00% |  |
PSUs | Maximum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Stock options vesting period | 2 years |  |
Payout percentage | 200.00% |  |
Restricted stock and performance share awards |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Unrecognized compensation cost | $ 917 |  |
Period for recognition | 2 years 2 months 12 days |  |
ESPP |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Shares available for future grant (in shares) | 5 |  |
Purchase price of common stock (percent) | 85.00% |  |
Issuances under employee stock purchase plan (in shares) | 2 |  |
Value of stock issued | $ 111 |  |
Capital shares reserved for future issuance (in shares) | 79 |  |
Deferred compensation plan | Fair value, recurring | Fair value |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Marketable equity securities | $ 261 | $ 218 |
Fair value at grant date | Restricted stock and performance share awards |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total fair value of vested stock awards as of vesting date | 503 | 479 | $ 450
Fair value at vesting date | Restricted stock and performance share awards |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Total fair value of vested stock awards as of vesting date | $ 471 | $ 459 | $ 372

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