Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 47,388	$ 42,633
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Provision for loan losses	4,000	0
Depreciation and amortization	11,968	10,144
(Recovery of) addition to valuation allowance on mortgage servicing rights, net	(5,216)	(2,371)
Amortization of mortgage servicing rights	4,989	6,417
Amortization of other intangible assets	1,011	1,049
Amortization and accretion on earning assets, funding, and other, net	14,069	16,149
Tax impact of stock-based compensation	59	5
(Gain) loss on sales of investment securities, net and impairment write-downs	(300)	(40)
(Gain) loss on sales of assets and impairment write-downs, net	(836)	3,594
Gain on mortgage banking activities, net	(15,493)	(10,477)
Mortgage loans originated and acquired for sale	(681,410)	(563,688)
Proceeds from sales of mortgage loans held for sale	779,022	620,895
(Increase) decrease in interest receivable	(3,226)	2,744
Increase (decrease) in interest payable	(7,276)	(9,574)
Net change in other assets and other liabilities	(15,337)	(5,715)
Net cash provided by (used in) operating activities	133,412	111,765
CASH FLOWS FROM INVESTING ACTIVITIES
Net (increase) decrease in loans	(179,438)	(251,508)
Purchases of:
Investment securities	(524,659)	(266,436)
Premises, equipment, and software, net of disposals	(16,223)	(12,149)
Other assets	(797)	(407)
Proceeds from:
Sales of investment securities	61,457	92,716
Prepayments, calls and maturities of investment securities	403,763	439,014
Sales, prepayments, calls, and maturities of other assets	23,784	9,204
Sales of loans originated for investment	12,172	0
Net cash provided by (used in) investing activities	(219,941)	10,434
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in deposits	481,429	562,721
Net increase (decrease) in short-term funding	(557,387)	(578,266)
Repayment of long-term funding	(100,076)	(125)
Proceeds from issuance of preferred stock		0
Cash dividends on common stock	(13,483)	(8,735)
Cash dividends on preferred stock	(1,300)	(1,300)
Purchase of treasury stock	(33,125)	(1,113)
Net cash provided by (used in) financing activities	(223,942)	(26,818)
Net increase (decrease) in cash and cash equivalents	(310,471)	95,381
Cash and cash equivalents at beginning of period	737,873	616,595
Cash and cash equivalents at end of period	427,402	711,976
Supplemental disclosures of cash flow information:
Cash paid for interest	24,946	35,461
Cash (received) paid for income taxes	0	(10,025)
Loans and bank premises transferred to other real estate owned	12,408	5,137
Capitalized mortgage servicing rights	$ 5,902	$ 5,895