STOCK-BASED COMPENSATION PLANS

The table below summarizes the components of total stock-based compensation for the years ended December 31 (in millions):



	2013		2012		2011
Stock options	$	3	$	2	$	3
Stock awards	10		11		8
Deferred stock awards	1		1		—
Employee stock purchase plan	2		1		1
Stock-based compensation	$	16	$	15	$	12

Tax benefit related to stock-based compensation	$	6	$	5	$	4

Unrecognized stock-based compensation for non-vested options and awards and the weighted-average period the expense will be recognized for the year ended December 31, 2013 (in millions):



	Amount		Weighted- Average Period
Stock options	$	2	0.6
Stock awards	7		0.7
Unrecognized stock-based compensation	$	9	0.7

The Company has various equity incentive plans under which it may grant stock awards to directors, officers and employees. The Company also has an employee stock purchase plan (ESPP).

The Company is authorized to issue 18 million shares of common stock under these plans and as of December 31, 2013, of which 8,939,315 shares remain available for future grants of either options or stock awards.

Stock Options

Stock options to purchase common stock are granted at the fair market value of the stock on the date of grant. The stock options granted have terms of up to ten years.

The fair value of each option grant was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions used for grants in the years ended December 31:



	2013			2012			2011
Expected volatility	67		%	55		%	56		%
Expected term	6 years			6 years			6 years
Risk-free interest rate	1.10		%	1.08		%	2.26		%
Expected dividend yield	—			—			—
Weighted-average grant date fair value per share	$	29.47		$	17.23		$	16.40
Estimated fair value of options granted (millions)	$	3		$	2		$	2

The expected market price volatility is based on the historical volatility. The expected term is based on the estimated period of time until exercise based on historical experience. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of the grant. The expected dividend yield is based on the estimated weighted average dividend yield over the expected term. The expected forfeiture rates are based on historical experience.

The tables below summarize stock option activity for the year ended December 31, 2013:



	Shares		Weighted- Average Exercise Price Per Share		Weighted- Average Contractual Life (Years)	Aggregate Intrinsic Value (in millions)
Outstanding, December 31, 2012	941,724		$	20.99	6.2	$	21
Granted	96,590		48.96
Exercised	(462,976	)	17.43
Forfeited or expired	(3,496	)	32.64
Outstanding, December 31, 2013	571,842		$	28.51	6.6	$	26

Exercisable, December 31, 2013	264,823		$	19.82	5.4	$	14
Vested or expected to vest, December 31, 2013	571,473		$	28.51	6.6	$	26



(in millions)	2013		2012		2011
Intrinsic value of option exercises	$	19	$	11	$	20
Cash received from stock option exercises	8		7		17
Tax benefit related to stock option exercises	7		4		8
Fair value of options vested	3		4		3

Stock Awards

Restricted stock units (RSUs) are awarded to eligible employees and entitle the grantee to receive shares of common stock at the end of the vest period. The fair value of the RSUs is based on the stock price on the date of grant. The RSUs “cliff vest” after three years, or the period from the date of grant to the employee’s retirement eligibility, and expense is recognized accordingly. Performance Share Unit (PSUs) are awarded to certain executives to receive shares of common stock if specific performance goals and market conditions are achieved. There are several tranches of PSUs which vest when performance goals and market conditions are met.

The following table summarizes information about outstanding stock awards:



	Number of Units		Weighted- Average Grant Date Fair Value		Weighted- Average Contractual Life (Years)	Aggregate Intrinsic Value (in millions)
Non-vested, December 31, 2012	754,293		$	28.06	0.6	$	33
Granted	208,110		49.10
Vested	(314,828	)	19.29
Forfeited	(8,360	)	33.66
Non-vested, December 31, 2013	639,215		$	39.15	0.6	$	47

Deferred Stock Awards

Deferred Stock Units (DSUs) are awarded to members of its Board of Directors as part of their retainers. The underlying common shares are issued upon retirement from the Board, but require no future service period. As a result, the entire intrinsic value of the awards is expensed on the date of grant.

Employee Stock Purchase Plan (ESPP)

The ESPP allows employees to purchase common stock at 85% of the stock price on the first day of the offering period or the specified purchase date, whichever is lower. Employees may contribute up to 10% of their base earnings during the offering period to purchase stock. Employees purchased 171,227, 157,373, and 125,564 shares in 2013, 2012, and 2011 under the ESPP.