Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

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

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range

The following table presents the number of options granted to purchase shares of the Company’s stock and the respective ranges of exercise prices per share and the weighted-average fair value of those granted options:

	Three Months Ended March 31,
	2015		2014
Options granted	133,279		116,990
Range of exercise prices, per share	$25.43 to $26.97		$19.55 to $21.57
Weighted-average fair value, per option	$	8.19	$	7.72

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of each option grant was established at the date of the grant using the Black-Scholes option pricing model, with the following assumptions:

	Three Months Ended March 31,
	2015		2014
Weighted-average risk-free interest rate	1.8	%	2.0	%
Expected dividend yield	1.1	%	—	%
Weighted-average volatility of Company's common stock	32.2	%	34.0	%
Weighted-average assumed forfeiture rate	9.0	%	10.3	%
Weighted-average expected term of options, in years	7.5		7.2
Options vesting annually	25.0	%	25.0	%

Schedule of Stock-based Compensation Expense and Related Tax Benefit

The following table details the Company's stock-based compensation expense and related tax benefit associated with this expense:

	Three Months Ended March 31,
(in thousands)	2015		2014
Stock-based compensation expense	$	61	$	51
Tax benefit associated with compensation expense	64		44