Share-Based Compensation - Additional Information (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				12 Months Ended	3 Months Ended		12 Months Ended
	Mar. 31, 2013 Stock options [Member]	Mar. 31, 2012 Stock options [Member]	Mar. 31, 2013 Restricted stock [Member] Installment	Mar. 31, 2012 Restricted stock [Member]	Dec. 31, 2012 Restricted stock [Member]	Mar. 31, 2013 Stock appreciation rights (SARs) [Member]	Mar. 31, 2012 Stock appreciation rights (SARs) [Member]	Dec. 31, 2006 Stock appreciation rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recorded for share based compensation	$ 5	$ 1	$ 72	$ 66		$ 4	$ 2
Maximum option term	10 years					10 years
General vesting period	3 years					3 years
Total intrinsic value of options exercised	0
Total intrinsic value of options outstanding	$ 110
Shares issued			0		62,105
Purchase price of long term restricted share			$ 0.00		$ 5.39
Forfeited due to employee terminations			0
Number of installment			2
Stock appreciation rights shares issued								30,000
Stock appreciation rights price of long term restricted share								$ 19.00
Shares expired due to employee terminations								15,500