Borrowings (Additional Information) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Borrowings [Abstract]
Line of credit, maximum borrowing capacity	$ 9,900	$ 9,900
Line of credit, amount outstanding	$ 0	$ 0
Line of credit, expiration date	Dec. 20, 2013