Equity Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Other Share-based Compensation, Activity

A summary of the equity awards granted for the three months ended March 31, 2017 and on April 1, 2017 is presented below.

Grant Date	Service Vesting Period	Stock Options	Restricted Stock
January 1 to March 31, 2017	Four-year graded vesting	2,669	525
April 1, 2017	Four-year graded vesting	1,300,007	248,489
April 1, 2017	Two-year graded vesting	47,030	11,272
		1,349,706	260,286

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of the stock options granted for the three months ended March 31, 2017 was estimated using a Black-Scholes valuation model that uses the weighted average assumptions noted in the following table. There were no stock options granted for the three months ended March 31, 2016.

	2017
Option pricing model		Black-Scholes
Expected volatility		19.16	%
Risk-free interest rate		1.84	%
Expected term in years		4.5
Dividend yield		—	%
Weighted average grant date fair value per stock option	$	16.09

Summary of Stock Options Outstanding

A summary of the stock options outstanding and exercisable as of December 31, 2016 and March 31, 2017 and changes during the interim period are presented below:

	Number of Options		Weighted Average Exercise Price		Aggregate Intrinsic Value
Outstanding at December 31, 2016	8,770,917		$	46.67	$	302.6
Granted	2,669		$	82.01
Exercised	(239,478	)	$	30.42	$	12.6
Cancelled or expired	(36,241	)	$	73.96
Outstanding at March 31, 2017	8,497,867		$	47.02	$	290.0
Exercisable at March 31, 2017	5,927,409		$	35.69	$	269.4
Exercisable at December 31, 2016	6,148,349		$	35.35	$	281.7

Summary of Restricted Stock Awards

A summary of the status of the restricted stock awarded under the 2013 Incentive Plan as of December 31, 2016 and March 31, 2017 and changes during the interim period are presented below:

	Number of Shares		Weighted Average Grant Date Fair Value Per Share
Outstanding at December 31, 2016	537,667		$	73.34
Granted	525		$	82.01
Vested	(8,444	)	$	80.03
Forfeited	(6,580	)	$	73.59
Outstanding at March 31, 2017	523,168		$	73.26