Stock-Based Compensation Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2015

Stock-Based Compensation Expense and Related Tax Benefit [Table Text Block]

For the three and nine months ended September 30, stock-based compensation expense and the related tax benefit were as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
	(in thousands)
Stock options	$	713	$	606	$	2,005	$	1,706
Restricted stock units	1,969		2,413		8,374		10,307
Unrestricted stock awards	200		230		500		690
Total stock-based compensation	$	2,882	$	3,249	$	10,879	$	12,703

Related tax benefit	$	809	$	850	$	3,189	$	3,523

Stock Options, Valuation Assumptions [Table Text Block]

The fair values of stock options granted were estimated at the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Dividend yield⁽¹⁾	—	%	—	%	—	%	—	%
Expected volatility⁽¹⁾	—	%	33.6	%	34.5	%	39.3	%
Risk-free interest rate⁽¹⁾	—	%	1.9	%	1.7	%	1.7	%
Expected term (years)⁽¹⁾	—		5.5		5.5		5.5

⁽¹⁾ There were no employee stock options granted for the three months ended September 30, 2015.

Employee Stock Options Activity [Table Text Block]

A summary of our stock option activity for the nine months ended September 30 is as follows:



	Shares		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value⁽¹⁾		Weighted Average Grant Date Fair Value
	(in thousands)				(years)	(in thousands)
Outstanding, January 1, 2014	1,180		$	54.79	4.6	$	1,300
Granted	160		35.65					$	13.65
Exercised	(41	)	26.17			546
Forfeited	(7	)	44.06
Expired	(141	)	69.24
Outstanding, September 30, 2014	1,151		$	51.42	5.1	$	1,011

Outstanding, January 1, 2015	1,123		$	51.90	4.4	$	1,676
Granted	207		35.30					$	12.15
Exercised	(23	)	36.05			26
Forfeited	(17	)	37.47
Expired	(167	)	53.95
Outstanding, September 30, 2015	1,123		$	49.12	5.4	$	—

Exercisable September 30, 2015	739		$	55.52	3.8	$	—

Expected to vest, September 30, 2015	374		$	36.86	8.7	$	—

⁽¹⁾

The aggregate intrinsic value of outstanding stock options represents amounts that would have been received by the optionees had all in- the-money options been exercised on that date. Specifically, it is the amount by which the market value of our stock exceeded the exercise price of the outstanding in-the-money options before applicable income taxes, based on our closing stock price on the last business day of the period. The aggregate intrinsic value of stock options exercised during the period is calculated based on our stock price at the date of exercise.

Restricted Stock Units, Valuation Assumptions

The weighted-average assumptions used to estimate the fair value of performance-based restricted stock units granted and the resulting weighted average fair value are as follows:



	Three Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
Dividend yield⁽¹⁾	—		%	—		%	—		%	—		%
Expected volatility⁽¹⁾	—		%	30.1		%	30.1		%	32.3		%
Risk-free interest rate⁽¹⁾	—		%	0.7		%	0.7		%	0.4		%
Expected term (years)⁽¹⁾	—			2.3			2.1			2.0

Weighted average fair value⁽¹⁾	$	—		$	43.05		$	33.48		$	35.15


⁽¹⁾	There were no long-term performance restricted stock units granted for the three months ended September 30, 2015.

Restricted Stock Units Award Activity [Table Text Block]

The following table summarizes restricted stock unit activity for the nine months ended September 30:



	Number of Restricted Stock Units		Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value⁽¹⁾
	(in thousands)				(in thousands)
Outstanding, January 1, 2014	658
Granted⁽²⁾	330		$	35.64
Released	(266	)			$	13,022
Forfeited	(29	)
Outstanding, September 30, 2014	693

Outstanding, January 1, 2015	682
Granted⁽²⁾	319		$	35.30
Released	(288	)			$	11,852
Forfeited	(54	)
Outstanding, September 30, 2015	659

Vested but not released, September 30, 2015	5				$	159

Expected to vest, September 30, 2015	537				$	17,131


⁽¹⁾	The aggregate intrinsic value is the market value of the stock, before applicable income taxes, based on the closing price on the stock release dates or at the end of the period for restricted stock units expected to vest.


⁽²⁾	Restricted stock units granted in 2014 and 2015 do not include awards under the Performance Award Agreement for the respective years, as these awards are not granted until attainment of annual performance goals has been determined at the conclusion of the performance period, which had not occurred as of September 30, 2014 and 2015, respectively.

Nonrestricted Stock Awards Activity [Table Text Block]

The following table summarizes unrestricted stock award activity for the three and nine months ended September 30:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
	(in thousands, except per share data)
Shares of unrestricted stock granted	6		6		14		18

Weighted average grant date fair value per share	$	33.91	$	41.42	$	36.51	$	39.19

Employee Stock Purchase Plan (ESPP) Activity [Table Text Block]

The following table summarizes ESPP activity for the three and nine months ended September 30:



	Three Months Ended September 30,		Nine Months Ended September 30,
	2015	2014	2015	2014
	(in thousands)
Shares of stock sold to employees⁽¹⁾	11	13	39	47


⁽¹⁾	Stock sold to employees during each fiscal quarter under the ESPP is associated with the offering period ending on the last day of the previous fiscal quarter.