Share-Based Compensation (Notes)

3 Months Ended

Mar. 31, 2016

Share-based Compensation [Abstract]

Disclosure of Compensation Related Costs, Share-based Payments

Share-Based Compensation

Stock Benefit Plans

We utilize the Black-Scholes option valuation model for estimating the fair value of our stock options. This model uses a range of assumptions related to volatility, the risk-free interest rate, the expected life, and the dividend yield. The fair values of our stock options are calculated using the following weighted average assumptions for the three months ended March 31, 2016:

Dividend yield	1.9	%
Expected volatility	19.5	%
Risk-free interest rate	1.0	%
Expected holding period (in years)	4.0

Stock Options

The following table sets forth stock option activity for the three months ended March 31, 2016:

	Options		Weighted-Average Exercise Price
Outstanding at December 31, 2015	11,047,920		$	13.98
Granted	1,036,522		$	22.28
Exercised	(417,383	)	$	7.51
Canceled	(7,064	)	$	20.97
Outstanding at March 31, 2016	11,659,995		$	14.94
Exercisable at March 31, 2016	8,559,885		$	12.62

As of March 31, 2016, the unrecognized compensation expense related to stock options of $9.6 million is expected to be recognized over a weighted average period of 1.4 years.

Restricted Shares

Restricted share activity for the three months ended March 31, 2016 was as follows:

	Restricted Shares		Weighted-Average Grant-Date Fair Value
Nonvested restricted shares at December 31, 2015	573,739		$	19.32
Granted	241,510		$	22.28
Vested	(306,000	)	$	18.06
Forfeited	(1,258	)	$	20.85
Nonvested restricted shares at March 31, 2016	507,991		$	21.48

As of March 31, 2016, the unrecognized compensation expense related to restricted shares of $10.0 million is expected to be recognized over a weighted average period of 2.2 years.