Share-Based Payments (Details 8) - Time-vested restricted stock units - $ / shares		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Time-vested restricted stock units
Beginning Balance, Unvested, Shares		1,137,000
Beginning Balance, Weighted Average Grant Date Fair Value		$ 221.01
Shares, Granted	[1]	459,000
Weighted Average Grant Date Fair Value, Granted		$ 388.88	[1]	$ 321.72	$ 176.53
Shares, Vested		(626,000)
Weighted Average Grant Date Fair Value, Vested		$ 190.65
Shares, Forfeited		(160,000)
Weighted Average Grant Date Fair Value, Forfeited		$ 302.35
Ending Balance, Unvested, Shares		810,000		1,137,000
Ending Balance, Weighted Average Grant Date Fair Value		$ 323.87		$ 221.01

[1] RSUs granted in 2015 primarily represent RSUs granted in conjunction with our annual awards made in February 2015 and awards made in conjunction with the hiring of new employees. RSUs granted in 2015 also include approximately 7,000 RSUs granted to our Board of Directors.