Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 49,014	$ 3,839
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,915	7,199
Provision for loan losses	15,991	60,036
(Gain) loss on other real estate owned	(54)	416
Deferred tax expense (benefit)	7,156	(8,041)
Increase in cash surrender value of life insurance contracts	(3,636)	(1,208)
Loss (gain) on disposal of other assets	229	(2,111)
Net decrease (increase) in loans held for sale	13,966	(3,308)
Net amortization of securities premium/discount	7,323	5,799
Amortization of intangible assets	4,705	5,124
Amortization of FDIC loss share receivable	1,100	1,613
Stock-based compensation expense	4,209	4,050
Decrease in interest payable and other liabilities	(33,323)	(8,438)
Net payments to FDIC for loss share claims	(1,131)	(302)
Decrease in FDIC loss share receivable	902	557
Decrease in other assets	21,362	27,488
Other, net	1,600	143
Net cash provided by operating activities	96,328	92,856
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities available for sale		47,774
Proceeds from maturities of securities available for sale	81,116	86,966
Purchases of securities available for sale	(60,484)	(167,419)
Proceeds from maturities of securities held to maturity	92,684	86,632
Purchases of securities held to maturity	(87,847)	(236,117)
Net decrease in short-term investments	9,428	414,004
Net increase in loans	(273,466)	(289,324)
Purchases of property and equipment	(7,329)	(1,550)
Proceeds from sales of property and equipment	17
Proceeds from sales of other real estate	3,099	4,316
Cash paid for acquisition, net of cash received	(322,708)
Other, net	(39,588)	3,567
Net cash used in investing activities	(605,078)	(51,151)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	99,583	307,254
Net increase (decrease) in short-term borrowings	385,777	(322,857)
Repayments of long-term debt	(4,475)	(19,551)
Issuance of long-term debt	41	66
Dividends paid	(20,793)	(19,131)
Cash paid for taxes with forfeited shares of stock	(163)	(127)
Proceeds from exercise of stock options	8,650
Proceeds from dividend reinvestment and stock purchase plan	755
Other, net		(134)
Net cash provided (used in) by financing activities	469,375	(54,480)
NET DECREASE IN CASH AND DUE FROM BANKS	(39,375)	(12,775)
CASH AND DUE FROM BANKS, BEGINNING	372,689	303,874
CASH AND DUE FROM BANKS, ENDING	333,314	291,099
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 1,031	$ 1,662