Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

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

Stock Based Compensation Expense

The following table discloses the amount of stock-based compensation expense for the three-month period ended March 31, 2014 and 2015:

	Three Months Ended March 31,
	2014		2015
Stock options	$	1,014	$	1,053
Restricted stock units		156		1,259
Performance based units		266		327
Total stock based compensation	$	1,436	$	2,639

Weighted-Average Assumptions

The fair value of the options granted was estimated at the date of grant using a Black-Scholes option pricing model with the following weighted-average assumptions:

	2014
Risk-free interest rate		2.00	%
Dividend yield		1.8	%
Expected volatility of the Company’s common stock		0.640
Expected life in years		6.0

Details of Stock Options Activity

The following table provides details of the stock option activity for the three months ended March 31, 2015:

	Number of Shares
Outstanding at January 1, 2015		1,765,922
Granted		—
Exercised		(745,665	)
Expired		(11,159	)
Canceled		(52,597	)
Outstanding at March 31, 2015		956,501
Exercisable		627,107

Details of Nonvested Restricted Stock Units Activity

The following table provides details of the nonvested restricted stock unit activity for the three months ended March 31, 2015:

	Number of Restricted Stock Units
Nonvested at January 1, 2015		197,838
Granted		108,052
Vested		(22,139	)
Canceled		(15,101	)
Accrued dividend equivalents		797
Nonvested at March 31, 2015		269,447

Performance Based Units Earned under Long-Term Incentive Plan

The following table provides details of the nonvested performance stock units under the Company’s Long-Term Incentive Plans:

	Number of Performance Stock Units
Performance stock units outstanding at January 1, 2015		83,515
Granted		114,385
Canceled		(7,234	)
Accrued dividend equivalents		246
Performance stock units outstanding at March 31, 2015		190,912