Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 93,089	$ 66,942
Adjustments to reconcile to net cash provided by operating activities:
Provision for loan losses	2,286	5,189
Depreciation and amortization	9,804	8,946
Net amortization of securities premiums and discounts	(141)	(108)
Realized securities (gains)/losses	(37)	352
Gain on sales of loans	(2,253)	(2,180)
Cash receipts from the sale of loans originated for sale	145,840	163,128
Cash disbursements for loans originated for sale	(142,207)	(163,460)
Deferred income tax provision (benefit)	83	(1,690)
(Gain)/loss on other assets	(341)	66
Increase in interest receivable	(2,380)	(1,651)
Increase in interest payable	764	188
Amortization of stock-based compensation arrangements	981	819
Excess tax benefit from stock-based compensation arrangements	(1,067)	(2,229)
Other, net	(4,994)	2,513
Net cash provided by operating activities	99,427	76,825
INVESTING ACTIVITIES
Net cash received from acquisitions, net of cash paid	6,248
Net decrease/(increase) in federal funds sold	22,948	(11,300)
Purchases of held for investment securities	(225)	(220)
Purchases of available for sale securities	(168,971)	(54,456)
Proceeds from maturities, calls and paydowns of held for investment securities	1,077	1,517
Proceeds from maturities, calls and paydowns of available for sale securities	121,581	72,853
Proceeds from sales of available for sale securities	31,286
Purchase of equity securities	(2,118)
Proceeds from paydowns and sales of equity securities	1,414
Net change in loans	81,000	(251,883)
Purchases of premises, equipment and computer software	(44,398)	(11,495)
Proceeds from the sale of other real estate owned and other assets	3,899	2,846
Net cash provided by/(used in) investing activities	53,741	(252,138)
FINANCING ACTIVITIES
Net change in deposits	(101,874)	53,989
Net increase in short-term borrowings	1,300	1,600
Issuance of common stock in connection with stock options, net	2,137	4,297
Cash dividends paid	(20,440)	(18,091)
Net cash (used in)/provided by financing activities	(118,877)	41,795
Net increase/(decrease) in cash, due from banks and interest-bearing deposits	34,291	(133,518)
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,757,875	1,850,461
Cash, due from banks and interest-bearing deposits at the end of the period	1,792,166	1,716,943
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	29,096	14,688
Cash paid during the period for income taxes	24,255	32,051
Noncash investing and financing activities:
Stock issued in acquisitions	39,498
Cash consideration for acquisitions	24,722
Fair value of assets acquired in acquisitions	377,320
Liabilities assumed in acquisitions	338,860
Unpaid common stock dividends declared	$ 9,823	$ 6,686