XML 99 R86.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stockholders' Equity - Repurchases of Common Stock (Details) - USD ($) $ / shares in Units, shares in Millions | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Apr. 30, 2016 | Feb. 29, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Jan. 31, 2015
Class of Stock [Line Items] |  |  |  |  |  |
Stock Repurchased and Retired During Period, Value |  |  | $ 954,000,000 | $ 11,001,000,000 | $ 10,002,000,000 |
Stock Repurchase, Average Cost Per Share |  |  | $ 71.79 | $ 89.15 | $ 104.91 |
2016 Stock Repurchase Program [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  | $ 12,000,000,000.0 |  |  |  |
Stock Repurchase Program, Remaining Authorized Repurchase Amount |  |  | $ 8,000,000,000 |  |  |
Stock Repurchased and Retired During Period, Shares |  |  |  | 36 |  |
Stock Repurchased and Retired During Period, Value |  |  |  | $ 3,000,000,000 |  |
2016 Stock Repurchase Program [Member] | Common Stock [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Stock Repurchased and Retired During Period, Shares |  |  | 13 |  |  |
Stock Repurchased and Retired During Period, Value |  |  | $ 954,000,000 |  |  |
2015 Stock Repurchase Program [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  | 5,000,000,000 |  |  |  | $ 15,000,000,000
Accelerated Share Repurchases, Settlement (Payment) or Receipt |  | $ 5,000,000,000 |  |  |  |
Accelerated Share Repurchases, Initial Price Paid Per Share |  | $ 86.68 |  |  |  |
Stock Repurchased and Retired During Period, Shares | 8 | 46 |  | 87 | 65 |
Stock Repurchase Program, Percentage of Shares Repurchased |  | 80.00% |  |  |  |
Stock Repurchased and Retired During Period, Value |  |  |  | $ 8,000,000,000 | $ 7,000,000,000 |
Accelerated Share Repurchases, Final Price Paid Per Share | $ 92.09 |  |  |  |  |
2014 Stock Repurchase Program [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  |  | $ 5,000,000,000 |
Stock Repurchased and Retired During Period, Shares |  |  |  |  | 30 |
Stock Repurchased and Retired During Period, Value |  |  |  |  | $ 3,000,000,000 |
Publicly Announced Program [Member] |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |
Stock Repurchased and Retired During Period, Shares |  |  | 13 | 123 | 95 |

X
- Definition Stock Repurchase Program, Percentage of Shares Repurchased + References No definition available. + Details
Name: | gild_StockRepurchaseProgramPercentageofSharesRepurchased
Namespace Prefix: | gild_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Final price paid per share for the purchase of the targeted number of shares, determined by an average market price over a fixed period of time. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653 + Details
Name: | us-gaap_AcceleratedShareRepurchasesFinalPricePaidPerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The price paid per share to immediately purchase the targeted number of shares on the date of executing the accelerated share repurchase agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653 + Details
Name: | us-gaap_AcceleratedShareRepurchasesInitialPricePaidPerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash receipt from (payment to) bank; or stock received from (issuance to) bank in the settlement of the accelerated share repurchase agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653 + Details
Name: | us-gaap_AcceleratedShareRepurchasesSettlementPaymentOrReceipt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount remaining of a stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of shares that have been repurchased and retired during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total cost of shares repurchased divided by the total number of shares repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 + Details
Name: | us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ShareRepurchaseProgramAxis=gild_A2016StockRepurchaseProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareRepurchaseProgramAxis=gild_A2015StockRepurchaseProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareRepurchaseProgramAxis=gild_A2014StockRepurchaseProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareRepurchaseProgramAxis=gild_PubliclyAnnouncedProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |