Mortgage Banking Activities, Components of Loans Held For Sale (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Components of Residential Mortgages Held For Sale Gross, Fair Value	$ 230,511	$ 325,102	$ 230,511	$ 325,102	$ 293,762
Number of days for past due loans (in days)	90 days		90 days
Mortgage Banking Revenue [Abstract]
Originating and marketing revenue	12,548	40,357	68,814	93,128
Servicing revenue	10,938	9,909	31,244	29,764
Mortgage banking revenue	23,486	50,266	100,058	122,892
Residential Mortgage Loans Held For Sale Gross [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Residential Mortgage Loans Held For Sale Unpaid Principal Balance, Gross	220,800	294,794	220,800	294,794	269,718
Components of Residential Mortgages Held For Sale Gross, Fair Value	228,926	313,927	228,926	313,927	281,935
Number of days for past due loans (in days)	90 days	90 days	90 days	90 days	90 days
Residential mortgage loans held for sale, nonperforming	0	0	0	0	0
Credit losses recognized on residential mortgage loans held for sale			0	0
Mortgage Banking Revenue [Abstract]
Originating and marketing revenue	31,047	40,463	79,045	85,262
Residential Mortgage Loan Commitments [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Residential Mortgage, Derivatives, Notional	351,196	452,129	351,196	452,129	356,634
Components of Residential Mortgages Held For Sale Gross, Fair Value	10,948	22,319	10,948	22,319	12,733
Minimum Number of Days Outstanding For Residential Mortgage Commitments	60 days	60 days	60 days	60 days	60 days
Maximum Number of Days Outstanding For Residential Mortgage Commitments	90 days	90 days	90 days	90 days	90 days
Mortgage Banking Revenue [Abstract]
Originating and marketing revenue	12,668	6,512	(1,774)	15,722
Forward Sales Contracts [Member]
Schedule of Residential Mortgage Loans Held For Sale [Line Items]
Residential Mortgage, Derivatives, Notional	560,069	722,043	560,069	722,043	598,442
Components of Residential Mortgages Held For Sale Gross, Fair Value	(9,363)	(11,144)	(9,363)	(11,144)	(906)
Minimum Number of Days for Delivery of Forward Sales Contracts	60 days	60 days	60 days	60 days	60 days
Maximum Number of Days for Delivery of Forward Sales Contracts	90 days	90 days	90 days	90 days	90 days
Mortgage Banking Revenue [Abstract]
Originating and marketing revenue	$ (31,167)	$ (6,618)	$ (8,457)	$ (7,856)