Share-Based Compensation (Notes)

6 Months Ended

Jun. 30, 2016

Share-based Compensation [Abstract]

Disclosure of Compensation Related Costs, Share-based Payments

Share-Based Compensation

Stock Benefit Plans

We maintain benefit plans whereby shares of our common stock may be issued pursuant to the exercise of stock options, restricted stock, or other stock based awards granted to officers and key employees. In May 2016, our shareholders approved the 2016 Equity Incentive Plan that reserves 13,000,000 shares of common stock for outstanding and future awards of stock options, restricted stock, and other stock based awards to officers and key employees.

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 six months ended June 30, 2016:

Dividend yield	2.0	%
Expected volatility	19.7	%
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 six months ended June 30, 2016:

	Options		Weighted-Average Exercise Price
Outstanding at December 31, 2015	11,047,920		$	13.98
Granted	1,863,700		$	22.28
Exercised	(871,422	)	$	10.18
Canceled	(19,798	)	$	20.98
Outstanding at June 30, 2016	12,020,400		$	15.53
Exercisable at June 30, 2016	8,153,847		$	12.67

As of June 30, 2016, the unrecognized compensation expense related to stock options of $14.8 million is expected to be recognized over a weighted average period of 1.5 years.

Restricted Stock Awards

Restricted stock awards activity for the six months ended June 30, 2016 was as follows:

	Restricted Stock Awards		Weighted-Average Grant-Date Fair Value
Nonvested restricted stock awards at December 31, 2015	573,739		$	19.32
Granted	241,510		$	22.28
Vested	(313,247	)	$	18.14
Forfeited	(1,258	)	$	20.85
Nonvested restricted stock awards at June 30, 2016	500,744		$	21.48

As of June 30, 2016, the unrecognized compensation expense related to restricted stock awards of $8.6 million is expected to be recognized over a weighted average period of 2.0 years.

Restricted Stock Units

Restricted stock units (RSU) activity for the six months ended June 30, 2016 was as follows:

	Restricted Stock Units		Weighted-Average Grant-Date Fair Value
Nonvested restricted stock units at December 31, 2015	—		$	—
Granted	130,660		$	25.72
Forfeited	(3,900	)	$	25.72
Nonvested restricted stock units at June 30, 2016	126,760		$	25.72

As of June 30, 2016, the unrecognized compensation expense related to restricted stock units of $3.2 million is expected to be recognized over a weighted average period of 2.6 years.