Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 50,442	$ 48,138
Adjustments to reconcile to net cash provided by operating activities:
Provision for loan losses	4,029	1,232
Depreciation and amortization	8,734	8,466
Net amortization of securities premiums and discounts	747	712
Realized securities gains	(7,121)	(819)
Gain on sales of loans	(1,534)	(1,387)
Cash receipts from the sale of loans originated for sale	132,957	114,388
Cash disbursements for loans originated for sale	(134,396)	(115,294)
Deferred income tax benefit	(1,029)	(3,107)
Gain on other assets	(76)	(714)
Decrease in interest receivable	8	381
Decrease in interest payable	(64)	(366)
Amortization of stock-based compensation arrangements	1,243	1,224
Other, net	4,797	6,957
Net cash provided by operating activities	58,737	59,811
INVESTING ACTIVITIES
Net decrease in federal funds sold		4,319
Net cash and due from banks received from acquisitions		174,283
Purchases of held for investment securities	(1,085)
Purchases of available for sale securities	(41,424)	(204,979)
Proceeds from maturities, calls and paydowns of held for investment securities	1,344	3,882
Proceeds from maturities, calls and paydowns of available for sale securities	53,285	197,469
Proceeds from sales of available for sale securities	8,576	2,235
Net change in loans	(113,740)	(266,076)
Purchases of premises, equipment and computer software	(9,535)	(8,541)
Proceeds from the sale of other assets	4,324	4,741
Net cash used in investing activities	(98,255)	(92,667)
FINANCING ACTIVITIES
Net change in deposits	(206,113)	19,116
Net (decrease)/increase in short-term borrowings	(205)	6,883
Paydown of long-term borrowings		(6,938)
Issuance of common stock, net	2,838	3,954
Cash dividends paid	(15,836)	(14,289)
Net cash (used in) provided by financing activities	(219,316)	8,726
Net decrease in cash, due from banks and interest-bearing deposits	(258,834)	(24,130)
Cash, due from banks and interest-bearing deposits at the beginning of the period	1,913,895	1,857,535
Cash, due from banks and interest-bearing deposits at the end of the period	1,655,061	1,833,405
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	9,142	10,058
Cash paid during the period for income taxes	26,531	21,128
Noncash investing and financing activities:
Unpaid common stock dividends declared	$ 5,609	$ 5,244