Stockholders' Equity - Treasury Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended									3 Months Ended	9 Months Ended
	Sep. 30, 2015	Aug. 31, 2015	Jul. 31, 2015	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Feb. 28, 2015	Jan. 31, 2015	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Jan. 01, 2015
Equity, Class of Treasury Stock [Line Items]
Total Number of Shares Purchased (shares)	163,708	156,408	182,826	138,432	38,898	0	230,532	1,234	16,031		928,069
Average Price Paid Per Share (usd per share)	$ 16.69	$ 16.63	$ 16.38	$ 16.98	$ 16.94	$ 0.00	$ 17.34	$ 16.98	$ 16.92		$ 16.84
Approximate Dollar Value of Shares That May Yet Be Purchased Under the Publicly Announced Plans or Programs	$ 3,224	$ 5,950	$ 8,545	$ 11,531	$ 13,876	$ 14,536	$ 14,536	$ 14,708	$ 14,729	$ 3,224	$ 3,224		$ 15,000
Common Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Total Number of Shares Purchased (shares)	163,708	156,408	182,826	138,432	38,898	0	10,202	1,234	16,031	502,942	707,739	707,739