Equity (Details of Stock Options) (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) $ / shares shares
Equity [Abstract]
Number of Options, Vested or expected to vest | shares	801,086
Weighted Average Exercise Price, Vested or expected to vest | $ / shares	$ 158.64
Weighted Average Remaining Contractual Life, Vested or expected to vest	6 years 4 months 7 days
Aggregate Intrinsic Value, Vested or expected to vest	$ 61
Number of Options, Exercised | shares	542,279
Weighted Average Exercise Price, Exercised | $ / shares	$ 137.50
Weighted Average Remaining Contractual Life, Exercised	5 years 2 months 6 days
Aggregate Intrinsic Value, Exercised	$ 53