Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 31, 2015	Feb. 28, 2015	Feb. 28, 2014	Feb. 28, 2013	May. 31, 2012
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)		$ 20
Preferred stock, shares outstanding (in shares)		0	0
Stock repurchased during period		$ 19,623	$ 10,000	$ 6,864
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)		500,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)		30,000
Preferred stock, voting rights		Each share of the Series A Preferred Stock shall entitle the holder to one thousand votes
Stock Repurchase Program 2012 [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount										$ 5,000
Stock repurchased during period (in shares)				30,601	312,527
Stock repurchased during period				$ 900	$ 4,100
Stock repurchase program, remaining authorized amount					$ 0
Stock Repurchase Program 2013 [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount									$ 6,000
Stock repurchased during period (in shares)				179,372
Stock repurchased during period				$ 6,000
Stock repurchase program, remaining authorized amount				$ 0
Stock Repurchase Program 2014 [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount								$ 10,000
Stock repurchased during period (in shares)			284,284
Stock repurchased during period			$ 10,000
Stock repurchase program, remaining authorized amount			$ 0
Stock Repurchase Program 2015 [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount						$ 10,000	$ 10,000
Stock repurchased during period (in shares)		551,791
Stock repurchased during period		$ 19,600
Stock repurchase program, remaining authorized amount		$ 400
Stock Repurchase Program 2015 [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Stock repurchased during period (in shares)	10,135
Stock repurchased during period	$ 400