Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net earnings	$ 234,011	$ 172,315
Depreciation and amortization	17,512	15,980
Amortization of net premiums on securities available-for-sale	14,164	20,227
Amortization of intangible assets	11,933	6,129
Provision for credit losses	21,500	36,227
Loss (gain) on sale of foreclosed assets	35	(282)
Provision for losses on foreclosed assets	65	14
Gain on sale of loans and leases	(4,675)	(1,361)
Gain on sale of premises and equipment	(8)	(565)
Gain on sale of securities	(6,564)	(1,552)
Gain on BOLI death benefit	(387)	(1,050)
Unrealized loss (gain) on derivatives and foreign currencies, net	20	(253)
Earned stock compensation	14,745	13,719
(Increase) decrease in deferred income taxes, net	(1,640)	7,823
Decrease (increase) in other assets	53,534	(50,973)
Decrease in accrued interest payable and other liabilities	(47,696)	(31,195)
Net cash provided by operating activities	306,549	185,203
Cash flows from investing activities:
Net increase in loans and leases	(95,306)	(388,619)
Proceeds from sales of loans and leases	643,261	83,798
Proceeds from maturities and paydowns of securities available-for-sale	157,806	217,399
Proceeds from sales of securities available-for-sale	368,775	86,018
Purchases of securities available-for-sale	(708,167)	(532,849)
Net purchases of Federal Home Loan Bank stock	(5,481)	(189)
Proceeds from sales of foreclosed assets	57	1,281
Purchases of premises and equipment, net	(7,332)	(4,037)
Proceeds from sales of premises and equipment	32	10,306
Proceeds from BOLI death benefit	313	2,478
Net decrease in equipment leased to others under operating leases	7,746	17,262
Net cash provided by (used in) investing activities	361,704	(507,152)
Cash flows from financing activities:
Net (decrease) increase in noninterest-bearing deposits	(379,436)	44,996
Net (decrease) increase in interest-bearing deposits	(554,453)	962,343
Net increase (decrease) in borrowings	719,884	(688,358)
Early Repayment of Subordinated Debt	(12,372)	0
Common stock repurchased and restricted stock surrendered	(249,007)	(7,558)
Cash dividends paid	(139,741)	(121,664)
Net cash (used in) provided by financing activities	(615,125)	189,759
Net increase (decrease) in cash, cash equivalents, and restricted cash	53,128	(132,190)
Cash, cash equivalents, and restricted cash, beginning of period	398,437	419,670
Cash, cash equivalents, and restricted cash, end of period	451,565	$ 287,480
Supplemental disclosures of cash flow information:
Cash paid for interest	47,569
Cash paid for income taxes	23,273
Loans transferred to foreclosed assets	1,059
Transfers from loans held for investment to loans held for sale	$ 0