Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2014

EQUITY INCENTIVE PLAN [Abstract]

Schedule of Stock Options, Activity

	Number of Options		Weighted Average Exercise Price	Aggregate Intrinsic Value (in millions)
Outstanding at December 31, 2013	1,871,694		$112.57	$243.7
Granted	123,226		263.62
Exercised	(335,848	)	62.67
Forfeited	(12,589	)	145.39
Outstanding at December 31, 2014	1,646,483		$133.80	$277.7
Options exercisable at December 31, 2014	1,221,408		$107.39	$238.3

Schedule Shares Outstanding under Stock Option Plans, by Exercise Price Range

Number of Options Outstanding	Weighted Average Exercise Price		Remaining Contractual Life of Options Outstanding	Options Exercisable
131,950	$	64.99	1.9	131,950
455,423	$	81.47	4.3	455,423
277,550	$	108.64	2.9	277,550
348,555	$	141.45	6.3	249,485
433,005	$	219.79	8.7	107,000
1,646,483			5.6	1,221,408

Schedule of Stock Options, Valuation Assumptions

	2014		2013		2012
Risk-free interest rate	1.66	%	1.31	%	0.71	%
Expected life in years	5.6		5		5
Expected volatility	28	%	28	%	30	%
Expected dividend yield	—		—		—

Schedule Restricted Stock Units, Activity

	Number of Restricted Stock Units		Aggregate Intrinsic Value (in millions)
Outstanding at December 31, 2013	107,782		$	26.1
Granted	29,683
Vested	(37,583	)
Forfeited	(3,785	)
Outstanding at December 31, 2014	96,097		$	29.1