CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flow From Operating Activities:
Net income	$ 159,139	$ 96,070	$ 81,051
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	7,227	9,143	5,657
Depreciation and amortization	8,842	7,967	7,161
Change in deferred taxes	3,524	15,523	8,611
Share-based compensation	3,592	2,827	2,600
Loans originated for sale	(372,791)	(377,252)	(354,265)
Proceeds from sales of loans held for sale	380,254	387,095	367,148
Gains on sales of loans held for sale	(5,025)	(5,910)	(5,918)
Gains on sales of securities available for sale	(4,269)	(2,631)	(3,389)
Increase in cash surrender of life insurance	(4,020)	(3,906)	(3,630)
Gains on life insurance benefits	(198)	(2,671)	(643)
Change in interest receivable	(3,751)	(6,838)	(1,779)
Change in interest payable	1,217	31	18
Other adjustments	6,494	7,054	1,097
Net cash provided by operating activities	180,235	126,502	103,719
Cash Flows from Investing Activities:
Net change in interest-bearing deposits	(1,936)	237,936	7,856
Purchases of:
Securities available for sale	(370,284)	(479,045)	(281,470)
Securities held to maturity	(30,465)	(30,220)	(110,797)
Proceeds from sales of securities available for sale	154,519	94,165	167,186
Proceeds from maturities of:
Securities available for sale	77,881	70,846	73,956
Securities held to maturity	66,129	72,220	119,052
Redemption (Purchase) of Federal Reserve and Federal Home Loan Bank stock	(763)	40	19,669
Net change in loans	(483,418)	(670,000)	(452,781)
Net cash and cash equivalents received in acquisition		54,536
Proceeds from the sale of other real estate owned	9,121	6,584	9,974
Proceeds from life insurance benefits	2,836	11,655	3,141
Other investing activities	804	(4,047)	(4,490)
Net cash used in investing activities	(575,576)	(635,330)	(448,704)
Net change in :
Demand and savings deposits	526,859	425,742	332,600
Certificates of deposit and other time deposits	55,204	75,236	(66,920)
Borrowings	1,515,526	1,088,189	1,107,795
Repayment of borrowings	(1,677,860)	(1,024,166)	(982,449)
Cash dividends on common stock	(41,660)	(31,820)	(22,203)
Stock issued under employee benefit plans	707	519	462
Stock issued under dividend reinvestment and stock purchase plans	1,211	991	835
Stock options exercised	1,598	2,398	2,602
Stock redeemed	(1,902)	(1,283)	(1,980)
Net cash provided by financing activities	379,683	535,806	370,742
Net Change in Cash and Cash Equivalents	(15,658)	26,978	25,757
Cash and Cash Equivalents, beginning of the year	154,905	127,927	102,170
Cash and Cash Equivalents, end of year	139,247	154,905	127,927
Additional cash flow information:
Interest paid	67,870	36,332	26,821
Income tax paid	23,289	22,421	11,999
Loans transferred to other real estate owned	855	8,360	1,684
Fixed assets transferred to other assets	374	6,753	360
Non-cash investing activities using trade date accounting	6,551	9,401	14,179
Investments transferred from held to maturity to available for sale in accordance with ASU 2017-12	30,794
Liabilities assumed in conjunction with acquisitions
Fair value of assets acquired	0	1,531,397	0
Cash received (paid) in acquisition		(12)
Less: Common stock issued		321,431
Liabilities assumed	$ 0	$ 1,209,954	$ 0