Investments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Investment in Marketable Securities
Current investments	$ 94	$ 113
Long-term investments	1,472	1,568
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses [Abstract]
Securities continuous unrealized losses less than 12 months - unrealized losses	18	0
Securities continuous unrealized losses greater than 12 months - unrealized losses	8	8
Securities continuous unrealized losses - unrealized losses	26	8
Available For Sale Securities Continuous Unrealized Loss Position Fair Value Abstract
Securities continuous unrealized losses less than 12 months - fair value	42	0
Securities continuous unrealized losses greater than 12 months - fair value	24	24
Securities continuous unrealized losses - fair value	66	24
Investments (Textuals) [Abstract]
Payments to acquire marketable securities	21	28	5
Gain on sale of investments, net	64	16	8
Impairment of marketable securities	180	1	6
Newmont equity interest ownership	40.00%
Securities continuous unrealized losses - unrealized losses	26	8
Current [Member]
Investment in Marketable Securities
Cost/Equity Basis	75	24
Unrealized Gain	20	89
Unrealized Loss	(1)
Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	625	555
Unrealized Gain	872	1,021
Unrealized Loss	(25)	(8)
Other investments, at cost	11	11
New Gold Inc. [Member]
Investments (Textuals) [Abstract]
Gain on sale of investments, net	50
New Gold Inc. [Member] | Current [Member]
Investment in Marketable Securities
Cost/Equity Basis		5
Unrealized Gain		54
Fair/Equity Basis - Current Marketable Equity Securities		59
Paladin Energy Ltd [Member]
Investments (Textuals) [Abstract]
Payments to acquire marketable securities	208
Impairment of marketable securities	148
Paladin Energy Ltd [Member] | Current [Member]
Investment in Marketable Securities
Cost/Equity Basis	60
Unrealized Gain	13
Unrealized Loss	0
Fair/Equity Basis - Current Marketable Equity Securities	73
Other Equity Securities [Member]
Investments (Textuals) [Abstract]
Payments to acquire marketable securities	73
Gain on sale of investments, net	14
Impairment of marketable securities	32	1
Other Equity Securities [Member] | Current [Member]
Investment in Marketable Securities
Cost/Equity Basis	15	19
Unrealized Gain	7	35
Unrealized Loss	(1)
Fair/Equity Basis - Current Marketable Equity Securities	21	54
Other Equity Securities [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	92	39
Unrealized Gain	16	37
Unrealized Loss	(17)
Fair/Equity Basis - Long-Term Marketable Equity Securities	91	76
Marketable Equity Securities [Member]
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses [Abstract]
Securities continuous unrealized losses less than 12 months - unrealized losses	18
Securities continuous unrealized losses greater than 12 months - unrealized losses	0
Securities continuous unrealized losses - unrealized losses	18
Available For Sale Securities Continuous Unrealized Loss Position Fair Value Abstract
Securities continuous unrealized losses less than 12 months - fair value	42
Securities continuous unrealized losses greater than 12 months - fair value	0
Securities continuous unrealized losses - fair value	42
Investments (Textuals) [Abstract]
Securities continuous unrealized losses - unrealized losses	18
Marketable Equity Securities [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	506	448
Unrealized Gain	871	1,018
Unrealized Loss	(17)
Fair/Equity Basis - Long-Term Marketable Equity Securities	1,360	1,466
Asset Backed Commercial Paper [Member]
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses [Abstract]
Securities continuous unrealized losses less than 12 months - unrealized losses	0	0
Securities continuous unrealized losses greater than 12 months - unrealized losses	6	6
Securities continuous unrealized losses - unrealized losses	6	6
Available For Sale Securities Continuous Unrealized Loss Position Fair Value Abstract
Securities continuous unrealized losses less than 12 months - fair value	0	0
Securities continuous unrealized losses greater than 12 months - fair value	19	19
Securities continuous unrealized losses - fair value	19	19
Investments (Textuals) [Abstract]
Securities continuous unrealized losses - unrealized losses	6	6
Asset Backed Commercial Paper [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	25	25
Unrealized Loss	(6)	(6)
Fair/Equity Basis - Long-Term Marketable Debt Securities	19	19
Auction Rate Securities [Member]
Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses [Abstract]
Securities continuous unrealized losses less than 12 months - unrealized losses	0	0
Securities continuous unrealized losses greater than 12 months - unrealized losses	2	2
Securities continuous unrealized losses - unrealized losses	2	2
Available For Sale Securities Continuous Unrealized Loss Position Fair Value Abstract
Securities continuous unrealized losses less than 12 months - fair value	0	0
Securities continuous unrealized losses greater than 12 months - fair value	5	5
Securities continuous unrealized losses - fair value	5	5
Investments (Textuals) [Abstract]
Securities continuous unrealized losses - unrealized losses	2	2
Auction Rate Securities [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	7	7
Unrealized Loss	(2)	(2)
Fair/Equity Basis - Long-Term Marketable Debt Securities	5	5
Corporate Debt Securities [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	10	7
Unrealized Gain	1	3
Fair/Equity Basis - Long-Term Marketable Debt Securities	11	10
Debt Securities [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	42	39
Unrealized Gain	1	3
Unrealized Loss	(8)	(8)
Fair/Equity Basis - Long-Term Marketable Debt Securities	35	34
Canadian Oil Sands Ltd [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	302	308
Unrealized Gain	401	508
Fair/Equity Basis - Long-Term Marketable Equity Securities	703	816
Gabriel Resources Ltd [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	76	78
Unrealized Gain	236	325
Fair/Equity Basis - Long-Term Marketable Equity Securities	312	403
Regis [Member] | Long Term [Member]
Investment in Marketable Securities
Cost/Equity Basis	36
Unrealized Gain	218
Fair/Equity Basis - Long-Term Marketable Equity Securities	254
La Zanja [Member] | Long Term [Member]
Investment in Marketable Securities
Equity Method Investments	66	57
AGR Matthey Joint Venture [Member]
Investments (Textuals) [Abstract]
Dividends from AGR		14
Gain from AGR dissolution		$ 6