Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities
Net income	$ 102,500	$ 75,677
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Provision for loan losses	5,810	5,400
Depreciation, amortization and accretion	3,689	3,541
Deferred income tax expense	7,335	1,669
Funding of mortgage loans held for sale	(1,318,484)	(1,256,233)
Proceeds from sales of mortgage loans held for sale	1,253,680	1,245,301
Gains on sales of mortgage loans held for sale	(30,805)	(15,719)
Losses (gains) on sales of securities	16	(57)
Penalty on prepayment of debt	0	205
(Gains) losses on sales of premises and equipment	(188)	553
Stock-based compensation expense	5,556	3,771
Increase in other assets	(57)	(2,059)
Decrease in other liabilities	(27,084)	(9,652)
Net cash provided by operating activities	1,968	52,397
Investing activities
Purchases of securities available for sale	(576,579)	(191,679)
Proceeds from sales of securities available for sale	2,387	43,494
Proceeds from call/maturities of securities available for sale	113,511	132,044
Proceeds from sales of securities held to maturity	0	4,876
Proceeds from call/maturities of securities held to maturity	0	15,882
Net increase in loans	(156,082)	(272,618)
Purchases of premises and equipment	(15,599)	(11,925)
Proceeds from sales of premises and equipment	912	1,255
Proceeds from sales of other assets	5,286	11,485
Net cash received in acquisition of businesses	153,502	41,685
Net cash used in investing activities	(472,662)	(225,501)
Financing activities
Net increase in noninterest-bearing deposits	90,240	6,464
Net increase in interest-bearing deposits	448,675	112,854
Net increase in short-term borrowings	51,606	274,554
Repayment of long-term debt	(643)	(169,961)
Cash paid for dividends	(31,242)	(25,004)
Net stock-based compensation transactions	201	173
Net cash provided by financing activities	558,837	199,080
Net increase in cash and cash equivalents	88,143	25,976
Cash and cash equivalents at beginning of period	281,453	306,224
Cash and cash equivalents at end of period	369,596	332,200
Supplemental disclosures
Cash paid for interest	43,317	26,974
Cash paid for income taxes	21,305	29,491
Noncash transactions:
Transfers of loans to other real estate owned	2,657	5,418
Financed sales of other real estate owned	495	257
Transfers of loans held for sale to loans held for investment	1,510	0
Common stock issued in acquisition of businesses	$ 434,519	$ 213,590