Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest Income
Interest and fees on loans	$ 383,545	$ 271,772	$ 209,429
Interest on investment securities:
Taxable	10,989	8,786	9,147
Tax-exempt	12,317	9,073	7,054
Dividends on nonmarketable equity securities	1,973	1,648	1,224
Interest on deposits with the Federal Reserve Bank, other banks and Federal funds sold	1,555	510	407
Total interest income	410,379	291,789	227,261
Interest Expense
Interest on deposits	23,021	15,406	14,254
Interest on short-term borrowings	1,660	453	414
Interest on long-term borrowings	4,617	1,922	42
Total Interest Expense	29,298	17,781	14,710
Net Interest Income	381,081	274,008	212,551
Provision for loan losses	14,875	6,500	6,100
Net interest income after provision for loan losses	366,206	267,508	206,451
Noninterest Income
Service charges and fees on deposit accounts	28,136	25,481	22,414
Wealth management revenue	22,601	20,552	16,015
Other charges and fees for customer services	30,246	25,513	18,928
Mortgage banking revenue	21,859	6,133	5,041
Net gain on sale of investment securities	129	630	0
Gain on sale of branch offices	7,391	0	0
Other	11,988	1,907	697
Total noninterest income	122,350	80,216	63,095
Operating Expenses
Salaries, wages and employee benefits	165,213	127,920	102,557
Occupancy	23,525	18,213	15,842
Equipment and software	24,408	18,569	14,737
Merger and acquisition-related transaction expenses	61,134	7,804	6,388
Other	64,138	51,388	40,401
Total operating expenses	338,418	223,894	179,925
Income before income taxes	150,138	123,830	89,621
Income tax expense	42,106	37,000	27,500
Net income	$ 108,032	$ 86,830	$ 62,121
Earnings per common share:
Basic (in dollars per share)	$ 2.21	$ 2.41	$ 1.98
Diluted (in dollars per share)	2.17	2.39	1.97
Cash Dividends Declared Per Common Share (in dollars per share)	$ 1.06	$ 1.00	$ 0.94