Income Taxes - Current and Deferred Tax (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Expense (Benefit) [Abstract]
Current	$ 97	$ 283	$ (639)
Deferred	13,727	2,422	(860)
Total income tax expense (benefit)	$ 13,824	$ 2,705	$ (1,499)