Capital Structure (Details) - USD ($) $ / shares in Units, $ in Thousands					1 Months Ended	12 Months Ended
	Oct. 24, 2014	Mar. 25, 2014	Jan. 08, 2013	Dec. 11, 2012	Oct. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 21, 2014
Class of Stock [Line Items]
Preferred stock, shares outstanding (shares)						0	0
Public offering, common stock shares (shares)				6,249,234
Public offering, by company (shares)				2,500,000
Public offering, by selling shareholders (shares)				3,749,234
Public offering, price per share (usd per share)				$ 6.39
Public offering, net proceeds			$ 4,100	$ 14,700		$ 0	$ 0	$ 4,118
Additional shares, overallotment option (shares)			687,385
Value of shares issued in business acquisition							1,279	1,472
Repurchases of common stock						18,071	22,685
Stock option exercises						$ 91	$ 2,823	$ 916
Common stock [Member]
Class of Stock [Line Items]
Public offering, by company (shares)								687,385
Shares issued for acquisition, shares							187,620	217,155
Value of shares issued in business acquisition							$ 2	$ 2
Stock repurchase program, shares authorized for repurchase (shares)	40,000,000.0	20,000,000.0			50,000,000				10,000,000.0
Share repurchase program, increase in shares authorized (shares)	20,000,000.0	10,000,000.0			10,000,000.0
Repurchases of common stock, shares						4,118,386	3,605,142
Repurchases of common stock						$ 41	$ 36
Stock option exercises, shares						29,128	716,780	202,159
Stock option exercises						$ 0	$ 7	$ 2