Share-Based Compensation - Components of Share Based Compensation Awards (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 554	$ 436	$ 1,059	$ 810
Income tax expense (benefit)	(185)	(115)	(349)	(234)
Total share-based compensation expense, net of income taxes	369	321	710	576
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	30	50	74	88
Income tax expense (benefit)	(2)	20	(5)	18
Total share-based compensation expense, net of income taxes	28	70	69	106
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	524	386	985	722
Income tax expense (benefit)	(183)	(135)	(344)	(252)
Total share-based compensation expense, net of income taxes	$ 341	$ 251	$ 641	$ 470