CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities
Net income	$ 50,433	$ 38,239
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based and non-cash compensation	1,935	1,309
Depreciation	6,084	5,330
Amortization of intangible assets	3,675	3,157
Provision for loan losses	2,494	4,050
Provision for deferred income taxes	(3,480)	(1,948)
Amortization of security premiums and discounts, net	4,172	5,407
Accretion of premiums and discounts on time deposits, trust preferred securities and borrowing, net	(232)	(529)
Accretion of premiums and discounts on portfolio loans, net	(6,329)	(4,329)
Net security gains	(1,143)	(1,230)
Gain on sales of mortgage loans, net of origination costs	(36,911)	(8,130)
Mortgage loans originated for sale	(1,166,083)	(1,218,032)
Proceeds from sales of mortgage loans	1,314,779	1,139,884
Net (gains) losses on disposition of premises and equipment	(57)	36
Premises and equipment impairment		650
Increase in cash surrender value of bank owned life insurance	(1,604)	(1,257)
Change in assets and liabilities:
Decrease in other assets	14,049	5,790
(Decrease) increase in other liabilities	(5,513)	1,125
Increase (decrease) in interest payable	1,650	(61)
Decrease (increase) in income taxes receivable	1,435	(1,073)
Net cash provided by (used in) operating activities before activities	179,354	(31,612)
Cash Flows from Investing Activities
Proceeds from sales of securities classified available for sale	134,515	49,378
Proceeds from sales of securities classified held to maturity		399
Proceeds from maturities of securities classified available for sale	154,435	183,329
Proceeds from maturities of securities classified held to maturity	6,358	1,333
Purchase of securities classified available for sale	(128,425)	(121,633)
Purchase of securities classified held to maturity	(185,201)	(2,103)
Net (increase) decrease in portfolio loans	(98,040)	62,154
Proceeds from disposition of premises and equipment	622	864
Proceeds from sale of other real estate owned ("OREO") properties	4,069	3,911
Purchases of premises and equipment	(11,336)	(6,748)
Net cash received in acquisitions	29,947	25,575
Proceeds from the redemption of Federal Home Loan Bank ("FHLB") stock	8,213	17,640
Purchase of FHLB stock	(3,891)	(23,478)
Net cash (used in) provided by investing activities	(88,734)	190,621
Cash Flows from Financing Activities
Net decrease in certificates of deposit	(92,596)	(131,917)
Net decrease in demand, money market and savings deposits	(42,414)	(48,112)
Net increase in securities sold under agreements to repurchase	4,443	16,551
Proceeds from short-term borrowings, net	53,150	67,700
Repayment of long-term advances	(39,800)	(4,906)
Net proceeds from issuance of senior debt	39,326
Net proceeds from issuance of subordinated debt	58,986
Cash dividends paid	(21,971)	(16,263)
Value of shares surrendered upon vesting to satisfy tax withholding obligations of stock-based compensation	(1,975)	(261)
Proceeds from stock options exercised	165
Common stock issuance costs	(259)	(246)
Net cash (used in) financing activities	(42,945)	(117,454)
Net increase in cash and cash equivalents	47,675	41,555
Cash and cash equivalents, beginning of period	166,706	319,280
Cash and cash equivalents, ending of period	214,381	360,835
Cash payments for:
Interest	11,485	6,658
Income taxes	19,369	13,900
Non-cash investing and financing activities:
Real estate acquired in settlement of loans	$ 477	$ 2,175