Stock Compensation Plans (Details 2) (Unaudited) (Stock Option Plan, USD $) In Millions, except Share data in Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2011 Year
Stock Option Plan
Stock Option Activity (Table Amounts)
Shares under option - outstanding at January 1, 2011	13,221
Shares under option - granted	805
Shares under option - exercised	(2,277)
Shares under option - cancelled and forfeited	(86)
Shares under option - Shipbuilding Spin-off adjustments	150
Shares under option - outstanding at September 30, 2011	11,813
Shares under option - vested and expected to vest in the future at September 30, 2011	11,785
Shares under option - exercisable at September 30, 2011	9,028
Weighted-average exercise price - outstanding at January 1, 2011	$ 55
Weighted-average exercise price - granted	$ 63
Weighted-average exercise price - exercised	$ 44
Weighted-average exercise price - cancelled and forfeited	$ 57
Weighted-average exercise price - Shipbuilding Spin-off adjustments	$ 59
Weighted-average exercise price - outstanding at September 30, 2011	$ 53
Weighted-average exercise price - vested and expected to vest in the future at September 30, 2011	$ 53
Weighted-average exercise price - exercisable at September 30, 2011	$ 52
Weighted-average remaining contractual term - outstanding at January 1, 2011 (Years)	3.8
Weighted-average remaining contractual term - outstanding at September 30, 2011 (Years)	3.6
Weighted-average remaining contractual term - vested and expected to vest in the future at September 30, 2011 (Years)	3.6
Weighted-average remaining contractual term - exercisable at September 30, 2011 (Years)	3.0
Aggregate intrinsic value - outstanding at January 1, 2011	$ 149
Aggregate intrinsic value - outstanding at September 30, 2011	48
Aggregate intrinsic value - vested and expected to vest in the future at September 30, 2011	48
Aggregate intrinsic value - exercisable at September 30, 2011	$ 42