Goodwill and Other Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Mortgage servicing rights:
Mortgage servicing rights at beginning of period	$ 84,209		$ 80,986		$ 56,025
Additions	17,476		26,165		44,580
Amortization	(25,830)		(22,942)		(19,619)
Mortgage servicing rights at end of period	75,855		84,209		80,986
Valuation allowance at beginning of period	(20,300)		(17,233)		(10,457)
Additions, net	(7,403)		(3,067)		(6,776)
Valuation allowance at end of period	(27,703)		(20,300)		(17,233)
Mortgage servicing rights, net	48,152		63,909		63,753
Fair value of mortgage servicing rights	48,152		64,378		66,710
Portfolio of residential mortgage loans serviced for others ("servicing portfolio")	7,321,000		7,453,000		7,667,000
Mortgage servicing rights, net to servicing portfolio	0.66%		0.86%		0.83%
Mortgage servicing rights expense	$ 33,233	[1]	$ 26,009	[1]	$ 26,395	[1]

[1] Includes the amortization of mortgage servicing rights and additions/recoveries to the valuation allowance of mortgage servicing rights, and is a component of mortgage banking, net in the consolidated statements of income (loss).