Share-Based Compensation - Components of Share Based Compensation Awards (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 552	$ 475	$ 1,611	$ 1,285
Income tax expense (benefit)	(186)	(152)	(535)	(386)
Total share-based compensation expense, net of income taxes	366	323	1,076	899
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	81	89	156	177
Income tax expense (benefit)	(21)	(17)	(26)	1
Total share-based compensation expense, net of income taxes	60	72	130	178
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	471	386	1,455	1,108
Income tax expense (benefit)	(165)	(135)	(509)	(387)
Total share-based compensation expense, net of income taxes	$ 306	$ 251	$ 946	$ 721