Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 50,746	$ 74,988
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,344	14,399
Provision for loan losses	77,232	12,762
Loss (gain) on other real estate owned	127	(374)
Deferred tax (benefit) expense	(10,663)	10,838
Increase in cash surrender value of life insurance contracts	(5,384)	(5,336)
(Gain) loss on disposal of other assets	(4,690)	1,694
Net increase in loans held for sale	(21,170)	(2,995)
Net amortization of securities premium/discount	12,905	9,741
Amortization of intangible assets	10,129	12,466
Amortization of FDIC indemnification asset	3,139	2,470
Stock-based compensation expense	7,164	6,353
Increase (decrease) in interest payable and other liabilities	(3,063)	(6,310)
Net payments (to) from FDIC for loss share claims	(159)	14,153
Decrease in FDIC loss share receivable	7,426	5,147
Decrease (increase) in other assets	37,117	(16,925)
Other, net	2,525	(2,338)
Net cash provided by operating activities	177,725	130,733
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of securities	102,335	9,230
Proceeds from maturities of securities available for sale	186,790	562,162
Purchases of securities available for sale	(461,139)	(1,083,192)
Proceeds from maturities of securities held to maturity	190,721	187,864
Purchases of securities held to maturity	(282,190)	(266,759)
Net decrease in short-term investments	412,396	204,493
Proceeds from sales of loans	106,660
Net increase in loans	(470,732)	(463,593)
Purchase of life insurance contracts	(40,000)
Purchases of property and equipment	(3,950)	(13,896)
Proceeds from sales of property and equipment	671	12,168
Proceeds from sales of other real estate	8,995	31,953
Other, net	2,989	(8,656)
Net cash used in investing activities	(246,454)	(828,226)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposits	467,973	728,957
Net decrease in short-term borrowings	(328,537)	(72,380)
Repayments of long-term debt	(28,836)	(17,600)
Net proceeds from issuance of long-term debt	5,885	145,296
Dividends paid	(38,238)	(38,704)
Purchase of common stock under stock buyback program		(75,270)
Proceeds from exercise of stock options		347
Issuance of stock from dividend reinvestment	36
Net cash provided by financing activities	78,283	670,646
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	9,554	(26,847)
CASH AND DUE FROM BANKS, BEGINNING	303,874	356,455
CASH AND DUE FROM BANKS, ENDING	313,428	329,608
SUPPLEMENTAL INFORMATION FOR NON-CASH INVESTING AND FINANCING ACTIVITIES
Assets acquired in settlement of loans	$ 10,526	$ 10,390