Transfers of Financial Assets and Mortgage Servicing Assets Loans sold (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Servicing Assets at Fair Value [Line Items]
Net gain on sale included as mortgage banking activities	$ 1,805	$ 665	$ 3,093	$ 13,584
Residential Portfolio Segment [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from the sale of loans held for sale	85,311	199,903	207,530	657,541
Net gain on sale included as mortgage banking activities	1,805	665	3,093	13,900
Loans sold with servicing rights retained	78,848	192,283	193,781	622,550
Commercial Portfolio Segment [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from the sale of loans held for sale	0	0	0	12,685
Net gain on sale included as mortgage banking activities	$ 0	$ 0	$ 0	$ (316)