Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows from Operating Activities
Net income	$ 81,180	$ 66,343
Adjustments to reconcile net income to net cash provided by/(used in) operating activities:
Credit for loan losses	(7,150)	(3,700)
Provision for losses on other real estate owned	368	1,616
Deferred tax liability	8,797	10,483
Depreciation and amortization	6,864	3,896
Net gains on sale and transfer of other real estate owned	(2,003)	(2,373)
Net gains on sale of loans	(763)	(216)
Proceeds from sales of loans	19,170	9,914
Originations of loans held-for-sale	(17,433)	(9,699)
Net change in trading securities		4,936
Write-downs on venture capital investments	327	268
Write-downs on impaired securities	3,875
Net gains on sales and calls of securities	(522)	(6,466)
Amortization/accretion of security premiums/discounts, net	1,770	1,723
Excess tax short-fall from share-based payment arrangements	5,619	1,177
Stock based compensation and stock issued to officers as compensation	2,738	1,997
Net change in accrued interest receivable and other assets	(15,041)	(6,644)
Net change in other liabilities	(1,423)	(6,529)
Net cash provided by operating activities	86,373	66,726
Cash Flows from Investing Activities
Decrease/(increase) in short-term investments	440,903	(286,638)
Purchase of investment securities available-for-sale	(1,223,504)	(350,834)
Proceeds from sale of investment securities available-for-sale	958,656	466,867
Proceeds from repayments, maturities and calls of investment securities available-for-sale	36,512	175,398
Purchase of Federal Home Loan Bank stock		(6,043)
Redemptions of Federal Home Loan Bank stock	13,535	5,371
Net increase in loans	(581,379)	(476,774)
Purchase of premises and equipment	(1,383)	(3,317)
Proceeds from sales of other real estate owned	10,139	17,931
Investment in affordable housing & alternative energy partnerships	(19,590)	(3,588)
Net cash used in investing activities	(366,111)	(461,627)
Cash Flows from Financing Activities
Net increase in deposits	555,369	599,146
Net decrease in federal funds purchased and securities sold under agreements to repurchase	(50,000)	(100,000)
Advances from Federal Home Loan Bank	4,632,000	6,452,400
Repayment of Federal Home Loan Bank borrowings	(4,847,000)	(6,452,400)
Cash dividends paid	(19,170)	(9,556)
Repayment of other borrowings		(2,000)
Proceeds from shares issued under Dividend Reinvestment Plan	2,752	875
Proceeds from exercise of stock options	1,713
Taxes paid related to net share settlement of RSUs	(204)	(274)
Excess tax short-fall from share-based payment arrangements	(5,619)	(1,177)
Net cash provided by financing activities	269,841	487,014
Increase in cash and cash equivalents	(9,897)	92,113
Cash and cash equivalents, beginning of the period	176,830	153,747
Cash and cash equivalents, end of the period	166,933	245,860
Cash paid during the period:
Interest	34,505	38,910
Income taxes paid	43,534	40,864
Non-cash investing and financing activities:
Net change in unrealized holding gain on securities available-for-sale, net of tax	2,046	21,096
Net change in unrealized holding gain/(loss) on cash flow hedge derivatives	740	(263)
Transfers to other real estate owned from loans held for investment	$ 866	$ 975