Mortgage Banking Operations (Servicing income)(Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Servicing Fees and Other	$ 7,955	$ 6,705	$ 15,562	$ 13,142
Changes in Fair Value of Mortgage Servicing Rights Due to Modeled Amortization	(6,569)	(4,052)	(11,675)	(9,022)
Amortization of Mortgage Servicing Rights (MSRs)	(423)	(462)	(913)	(953)
Net Servicing Income	963	2,191	2,974	3,167
Servicing Asset at Fair Value, Other Changes in Fair Value	14,725	(15,354)	18,304	(7,942)
Derivative Instruments, Gain (Loss) Recognized in Income, Net	7,509	24,119	3,626	30,304
Mortgage servicing rights, risk management	1,220	4,900	2,281	11,797
Servicing Fees, Net	2,183	7,091	5,255	14,964
Servicing Contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ (13,505)	$ 20,254	$ (16,023)	$ 19,739