Summary Of Significant Accounting Policies (Reconciliation Of The Numerator And Denominator Used In The Calculation Of Basic And Diluted Net Income Per Share) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income Attributable to Gilead	$ 441,956	$ 651,141
Weighted-average shares of common stock outstanding used in the calculation of basic net income per share attributable to Gilead common stockholders	756,286	796,115
Effect of dilutive securities, stock options and equivalents	14,873	15,007
Weighted-average shares of common stock outstanding used in the calculation of diluted net income per share attributable to Gilead common stockholders	777,388	811,857
May 2011 Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities, conversion spread	0	224
May 2013 Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities, conversion spread	3,423	511
Convertible Senior Notes Due In May 2014 Member
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities, conversion spread	1,505	0
Convertible Senior Notes Due In May 2016 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of dilutive securities, conversion spread	1,301	0

Summary Of Significant Accounting Policies (Reconciliation Of The Numerator And Denominator Used In The Calculation Of Basic And Diluted Net Income Per Share) (Details) (USD $)
In Thousands, unless otherwise specified

3 Months Ended

Mar. 31, 2012

Mar. 31, 2011

Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]

Net income Attributable to Gilead

$ 441,956

$ 651,141

Weighted-average shares of common stock outstanding used in the calculation of basic net income per share attributable to Gilead common stockholders

756,286

796,115

Effect of dilutive securities, stock options and equivalents

14,873

15,007

Weighted-average shares of common stock outstanding used in the calculation of diluted net income per share attributable to Gilead common stockholders

777,388

811,857

May 2011 Notes [Member]

Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]

Effect of dilutive securities, conversion spread

224

May 2013 Notes [Member]

Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]

Effect of dilutive securities, conversion spread

3,423

511

Convertible Senior Notes Due In May 2014 Member

Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]

Effect of dilutive securities, conversion spread

1,505

Convertible Senior Notes Due In May 2016 [Member]

Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]

Effect of dilutive securities, conversion spread

1,301

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

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+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Weighted-Average Number of Common Shares Outstanding

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+ Details