Stock Repurchase Program (Details) (USD $) Share data in Thousands, unless otherwise specified	1 Months Ended		3 Months Ended		12 Months Ended
	Sep. 30, 2012	Dec. 31, 2007	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2008
Class of Stock [Line Items]
Stock Repurchase Program expiration date			Sep. 20, 2013
Stock Repurchase Program (Textual) [Abstract]
Stock Repurchase Program	$ 16,100,000	$ 5,000,000	$ 3,900,000		$ 13,500,000
Additional authorized amount stock repurchase program			2,600,000
Repurchase of common stock			164	69
Aggregate purchase price common stock Shares			$ 661,000	$ 260,000
Prior Stock Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program expiration date			Sep. 21, 2012