Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash Flows from Operating Activities
Net income	$ 31,259	$ 28,998
Adjustments to reconcile net income to net cash provided by/(used in) operating activities:
Provision/(credit) for losses on other real estate owned	617	(37)
Deferred tax liabilities	6,012	6,227
Depreciation	1,742	1,527
Net (gains)/losses on sale and transfer of other real estate owned	(559)	44
Net gains on sale of loans	(128)	(567)
Proceeds from sales of loans	4,525	23,672
Originations of loans held-for-sale	(4,397)	(23,105)
Net change in trading securities	4,936	(55)
Write-downs on venture capital investments	75	92
Gain on sales and calls of securities	(5,960)	(6,292)
Amortization/accretion of security premiums/discounts, net	867	1,114
Amortization of other intangible assets	196	1,428
Excess tax short-fall from share-based payment arrangements	1,227	69
Stock based compensation and stock issued to officers as compensation	1,353	1,037
Net change in accrued interest receivable and other assets	3,285	4,081
Net change in other liabilities	1,374	1,612
Net cash provided by operating activities	46,424	39,845
Cash Flows from Investing Activities
(Increase)/decrease in short-term investments	(103,368)	196,189
Purchase of investment securities available-for-sale	(246,498)	(508,865)
Proceeds from sale of investment securities available-for-sale	139,671	320,234
Proceeds from repayments, maturities and calls of investment securities available-for-sale	133,369	57,495
Proceeds from repayments, maturities and calls of investment securities held-to-maturity		50,973
(Purchase)/redemption of Federal Home Loan Bank stock	(4,901)	4,142
Net (increase)/decrease in loans	(220,402)	61,833
Purchase of premises and equipment	(2,081)	(1,014)
Proceeds from sale of other real estate owned	6,379	1,351
Net increase in investment in affordable housing	(1,894)	(1,614)
Net cash (used in)/provided by investing activities	(299,725)	180,724
Cash Flows from Financing Activities
Net increase in deposits	251,032	42,362
Net decrease in federal funds purchased and securities sold under agreements to repurchase	(100,000)	(100,000)
Advances from Federal Home Loan Bank	5,127,400	298,020
Repayment of Federal Home Loan Bank borrowings	(5,012,400)	(317,500)
Cash dividends paid	(3,980)	(3,828)
Redemption of series B preferred stock		(129,000)
Proceeds from shares issued under Dividend Reinvestment Plan	386	62
Excess tax short-fall from share-based payment arrangements	(1,227)	(69)
Net cash provided by/(used in) financing activities	261,211	(209,953)
Increase in cash and cash equivalents	7,910	10,616
Cash and cash equivalents, beginning of the period	153,747	144,909
Cash and cash equivalents, end of the period	161,657	155,525
Cash paid during the period:
Interest	19,533	22,827
Income tax	12,444	8,562
Non-cash investing and financing activities:
Net change in unrealized holding gain on securities available-for-sale, net of tax	7,639	23,012
Transfers investment securities to available-for-sale from held-to-maturity		722,466
Transfers to other real estate owned from loans held for investment		366
Loans to facilitate the sale of other real estate owned		$ 75