Mortgage Servicing Rights - At Fair Value (Details) (Mortgage loans, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Mortagage servicing rights, fair value	$ 16,373
Servicing asset at fair value, assumptions used to estimate fair value, weighted average life	4 years 4 months 21 days
Minimum
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Servicing assets at fair value, assumptions used to estimate fair value, discount rate	8.50%
Servicing assets at fair value, assumptions used to estimate fair value, prepayment speed	0.70%
Maximum
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Servicing assets at fair value, assumptions used to estimate fair value, discount rate	21.00%
Servicing assets at fair value, assumptions used to estimate fair value, prepayment speed	6.10%