Mortgage Servicing Rights (Details 2) (USD $) In Thousands, unless otherwise specified			3 Months Ended		9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 MSRs	Sep. 30, 2012 MSRs	Sep. 30, 2013 MSRs	Sep. 30, 2012 MSRs
Amortized cost:
Amortized cost at beginning of period	$ 226,090	$ 89,177	$ 179,003	$ 30,305	$ 92,155	$ 6,496
Servicing resulting from loan sales			55,981	25,590	150,175	50,234
Amortization			(5,367)	(1,127)	(12,713)	(1,962)
Amortized cost at end of period	226,090	89,177	229,617	54,768	229,617	54,768
Valuation allowance for impairment of MSRs:
Balance at beginning of period			(2,335)	(854)	(2,978)	(70)
Additions			(1,192)	(1,000)	(549)	(1,784)
Balance at of period end			(3,527)	(1,854)	(3,527)	(1,854)
Additional disclosures
MSRs, net			226,090	52,914	226,090	52,914
Estimated fair value of MSRs at of period end			239,326	53,419	239,326	53,419
Estimated amortization
2014			22,633		22,633
2015			21,637		21,637
2016			20,658		20,658
2017			19,910		19,910
2018			18,859		18,859
Thereafter			125,920		125,920
Total			$ 229,617		$ 229,617