Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Income:
Interest and fees on loans	$ 260,506	$ 229,147	$ 194,345
Interest on mortgage-backed securities	26,065	19,308	15,754
Interest and dividends on investment securities
Taxable	61	137	321
Tax-exempt	4,317	4,511	4,551
Other interest income	2,024	1,623	1,607
Total interest income	292,973	254,726	216,578
Interest Expense:
Interest on deposits	29,068	14,904	9,421
Interest on Federal Home Loan Bank advances	8,395	8,263	4,707
Interest on senior debt	4,717	7,228	6,356
Interest on trust preferred borrowings	2,573	1,940	1,622
Interest on federal funds purchased	1,695	972	606
Interest on other borrowings	51	148	121
Total interest expense	46,499	33,455	22,833
Net interest income	246,474	221,271	193,745
Provision for loan losses	13,170	10,964	12,986
Net interest income after provision for loan losses	233,304	210,307	180,759
Noninterest Income:
Loan fee income	2,492	2,218	2,066
Security gains, net	21	1,984	2,369
Unrealized gains on equity investments	20,745	0	0
Realized gain on sale of equity investment	3,757	0	0
Bank owned life insurance income	175	1,545	919
Total non interest income	162,541	124,644	105,061
Noninterest Expense:
Salaries, benefits and other compensation	122,983	114,376	95,983
Occupancy expense	19,783	19,409	16,646
Equipment expense	12,609	12,564	10,368
Professional fees	8,733	8,597	9,142
Data processing and operations expenses	7,757	6,779	6,275
Marketing expense	4,586	3,083	3,020
FDIC expenses	2,117	2,216	2,606
Loan workout and OREO expenses	1,548	1,820	1,681
Corporate development expense	6,456	878	8,529
(Recovery of) provision for legal settlement	(7,938)	12,000	0
(Recovery of) provision for fraud loss	(1,675)	2,844	0
Early extinguishment of debt costs	0	695	0
Other operating expense	48,088	41,200	34,416
Total non interest expenses	225,047	226,461	188,666
Income before taxes	170,798	108,490	97,154
Income tax provision	36,055	58,246	33,074
Net income	$ 134,743	$ 50,244	$ 64,080
Basic (in dollars per share)	$ 4.27	$ 1.60	$ 2.12
Diluted (in dollars per share)	$ 4.19	$ 1.56	$ 2.06
Credit/debit card and ATM income
Noninterest Income:
Noninterest income	$ 43,837	$ 36,116	$ 29,899
Investment management and fiduciary income
Noninterest Income:
Noninterest income	39,602	35,103	25,691
Deposit service charges
Noninterest Income:
Noninterest income	18,771	18,318	17,734
Mortgage banking activities, net
Noninterest Income:
Noninterest income	6,286	6,293	7,434
Other income
Noninterest Income:
Noninterest income	$ 26,855	$ 23,067	$ 18,949