Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net earnings	$ 90,456		$ 73,079
Depreciation and amortization	22,488		10,648
Provision for credit losses	20,140	$ 13,772	16,434
(Gain) loss on sale of foreclosed assets	(504)		106
Provision for losses on foreclosed assets	0		124
Gain on sale of loans and leases	(245)	(183)	0
Gain on sale of premises and equipment	(6)		(3)
Gain on sale of securities	(8,110)		(3,275)
Unrealized gain on derivatives and foreign currencies, net	(250)		(2,715)
Earned stock compensation	5,046		3,112
Gain (Loss) on Sale of Capital Leases, Net	720		0
Tax effect included in stockholders' equity of restricted stock vesting	(3,795)		0
Decrease in accrued and deferred income taxes, net	24,726		38,722
Decrease in other assets	5,214		19,356
Decrease in accrued interest payable and other liabilities	(23,722)		(29,102)
Net cash provided by operating activities	132,158		126,486
Net Cash Provided by (Used in) Investing Activities [Abstract]
Net increase in loan and leases	(170,465)		(403,438)
Proceeds from sales of loans and leases	26,903		0
Proceeds from maturities and paydowns	61,626		27,547
Proceeds from sales	343,031		144,945
Purchases	(52,236)		(196,568)
Net redemptions of Federal Home Loan Bank stock	2,460		11,704
Proceeds from sales of foreclosed assets	4,443		7,945
Purchases of premises and equipment, net	(2,896)		(1,490)
Proceeds from sales of premises and equipment	6		29
Proceeds from Sale and Collection of Lease Receivables	138,809		0
Proceeds from Life Insurance Policies	1,853		0
Net increase of equipment leased to others under operating leases	(12,300)		0
Net cash provided by (used in) investing activities	341,234		(409,326)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Noninterest-bearing	(31,310)		97,224
Interest-bearing	(193,315)		80,914
Net (decrease) increase in borrowings	(68,483)		234,754
Restricted stock surrendered	(141)		0
Tax effect included in stockholders' equity of restricted vesting stock	3,795		0
Cash dividends paid	(60,906)		(51,424)
Net cash (used in) provided by financing activities	(350,360)		361,468
Net increase in cash and cash equivalents	123,032		78,628
Cash and cash equivalents at beginning of period	396,486		313,226
Cash and cash equivalents at end of period	519,518	$ 396,486	391,854
Noncash transactions from investing activities:
Cash paid for interest	15,080		12,334
Income Taxes Paid, Net	15,773		(7,695)
Loans transferred to foreclosed assets	$ 129		$ 394