Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest income
Interest and fees on loans	$ 83,608	$ 67,184
Interest Income, Securities, Operating, Taxable	7,465	6,219
Nontaxable interest and dividends on securities	13	16
Interest on loans held for sale	31	19
Interest on federal funds sold and short-term investments	426	311
Total interest and dividend income	91,543	73,749
Interest expense
Interest on deposits	7,028	3,935
Interest on borrowings	1,990	1,343
Total interest expense	9,018	5,278
Net interest income	82,525	68,471
Provision for loan losses	1,000	500
Net interest income after provision for loan losses	81,525	67,971
Noninterest income
Deposit account fees	4,406	4,431
Interchange and ATM fees	4,516	4,173
Investment Banking, Advisory, Brokerage, and Underwriting Fees and Commissions	6,748	6,142
Mortgage banking income	806	870
Increase in cash surrender value of life insurance policies	972	947
Loan level derivative income	641	447
Other noninterest income	3,444	2,853
Total noninterest income	21,533	19,863
Noninterest expenses
Salaries and employee benefits	33,117	31,100
Occupancy and equipment expenses	7,130	7,408
Data processing & facilities management	1,326	1,286
FDIC assessment	616	798
Advertising expense	1,213	1,123
Business Combination, Acquisition Related Costs	1,032	0
Software Maintenance	1,165	972
Other noninterest expenses	10,712	10,764
Total noninterest expenses	56,311	53,451
Income before income taxes	46,747	34,383
Provision for income taxes	11,522	6,828
Net income	$ 35,225	$ 27,555
Basic earnings per share (in dollars per share)	$ 1.25	$ 1.00
Diluted earnings per share (in dollars per share)	$ 1.25	$ 1.00
Weighted average common shares (basic) (in shares)	28,106,184	27,486,573
Common shares equivalents (in shares)	54,466	67,381
Weighted average common shares (diluted) (in shares)	28,160,650	27,553,954
Retained Earnings [Member]
Noninterest expenses
Net income	$ 35,225	$ 27,555
Cash dividends declared per common share (in dollars per share)	$ 0.44	$ 0.38