Debt (Details Textual) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jul. 02, 2012	Jun. 30, 2012	Jan. 06, 2012	Dec. 31, 2011
Debt (Textual) [Abstract]
Convertible debt instrument, coupon rate	6.00%	6.00%
Outstanding borrowings under revolving credit facility	$ 25,000,000	$ 25,000,000
Additional available borrowing capacity	55,800,000	55,800,000
Outstanding convertible notes due on July 2, 2012		91,875,000	91,900,000	91,875,000
Pre-established trading-day observation period		40 days
Conversion price	$ 21.78	$ 21.78				$ 21.78
Average Stock Price	30.00
Revolving loans in a collective maximum principal amount					$ 100,000,000
Common stock, shares issued	15,729,152	15,729,152	1,061,745			15,602,132
Convertible notes, maturity dates		Jul. 02, 2012