Share-Based Compensation - Components of Share Based Compensation Awards (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 505	$ 374
Income tax expense (benefit)	(164)	(119)
Total share-based compensation expense, net of income taxes	341	255
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	44	38
Income tax expense (benefit)	(3)	(2)
Total share-based compensation expense, net of income taxes	41	36
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	461	336
Income tax expense (benefit)	(161)	(117)
Total share-based compensation expense, net of income taxes	$ 300	$ 219