Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES
Net income	$ 86,635	$ 80,762	$ 69,974
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of premises and equipment	9,242	8,122	7,386
Other net amortization	8,768	6,460	1,742
Provision for credit losses	8,478	8,353	6,405
Net securities gains	(2,357)	(948)	(903)
Net gains on sales of mortgage loans	(2,529)	(2,071)	(1,604)
Decrease in deferred income tax assets	10,824	10,665	8,690
Increase in cash surrender value of bank-owned life insurance	(4,064)	(4,863)	(4,614)
Contribution to pension plan	(5,750)	(7,500)	(7,500)
Loans originated for sale	(167,370)	(135,892)	(102,321)
Proceeds from the sale of loans originated for sale	159,831	135,928	103,916
Net change in: accrued interest receivable and other assets	13,137	(4,293)	10,205
Net change in: accrued interest payable and other liabilities	7,404	(7,988)	(1,896)
Other-net	1,448	1,914	5,328
Net cash provided by operating activities	123,697	88,649	94,808
INVESTING ACTIVITIES
Net increase in loans held for investment	(174,952)	(293,306)	(199,760)
Securities available-for-sale:
Proceeds from sales	277,225	635,609	16,249
Proceeds from maturities, prepayments and calls	285,318	319,370	214,934
Purchases of securities	(214,514)	(526,765)	(201,272)
Securities held-to-maturity:
Proceeds from maturities, prepayments and calls	110,954	75,295	47,820
Purchases of securities	(93,444)	(390,471)	(45,955)
Net cash received (paid) to acquire a business	4,863	(28,551)
Proceeds from bank-owned life insurance	19	7,803	2,352
Purchases of premises and equipment-net	(2,061)	(9,575)	(7,374)
Sale of portfolio loans-net	560
Net cash provided (used in) by investing activities	193,968	(210,591)	(173,006)
FINANCING ACTIVITIES
Decrease in deposits	(216,785)	(233,684)	(12,869)
Proceeds from Federal Home Loan Bank borrowings	140,000	941,910	200,532
Repayment of Federal Home Loan Bank borrowings	(233,988)	(515,388)	(16,775)
Increase (decrease) in other short-term borrowings	15,711	(4,334)	(51,021)
Increase (decrease) in federal funds purchased	58,000		(20,000)
Repayment of junior subordinated debt		(36,083)
Repurchase of common stock warrant		(2,247)
Dividends paid to common shareholders	(37,805)	(33,007)	(25,136)
Issuance of common stock	1,713
Treasury shares (purchased) sold-net	(3,026)	(2,542)	1,918
Net cash (used in) provided by financing activities	(276,180)	114,625	76,649
Net increase (decrease) in cash and cash equivalents	41,485	(7,317)	(1,549)
Cash and cash equivalents at beginning of the year	86,685	94,002	95,551
Cash and cash equivalents at end of the year	128,170	86,685	94,002
SUPPLEMENTAL DISCLOSURES
Interest paid on deposits and other borrowings	34,028	27,969	24,521
Income taxes paid	22,075	15,855	11,706
Transfers of loans to other real estate owned	4,757	1,501	$ 2,464
Transfers of portfolio loans to loans held for sale	560
Non-cash transactions related to YCB and ESB acquisitions	$ 177,149	$ 301,933