Share-Based Payments (Details 4) - Market stock units - $ / shares		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Market stock units activity
Beginning Balance, Unvested, Shares		403,000
Beginning Balance, Weighted Average Grant Date Fair Value		$ 219.29
Shares, Granted	[1]	185,000
Weighted Average Grant Date Fair Value, Granted		$ 493.43	[1]	$ 395.22	$ 193.45
Shares, Vested		(277,000)
Weighted Average Grant Date Fair Value, Vested		$ 165.63
Shares, Forfeited		(42,000)
Weighted Average Grant Date Fair Value, Forfeited		$ 294.85
Ending Balance, Unvested, Shares		269,000		403,000
Ending Balance, Weighted Average Grant Date Fair Value		$ 339.89		$ 219.29

[1] MSUs granted in 2015 include approximately 8,000, 19,000, 24,000 and 34,000 MSUs issued in 2015 based upon the attainment of performance criteria set for 2014, 2013, 2012 and 2011, respectively, in relation to awards granted in those years. The remainder of MSUs granted during 2015 include awards granted in conjunction with our annual awards made in February 2015 and MSUs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant.