CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Interest income:
Interest and fees on loans	$ 52,509	$ 45,791	$ 104,159	$ 91,382
Interest and dividends on taxable investments	14,016	13,288	27,612	25,348
Interest on nontaxable investments	4,585	4,801	9,095	9,604
Total interest income	71,110	63,880	140,866	126,334
Interest expense:
Interest on deposits	1,872	1,731	3,766	3,531
Interest on borrowings	210	294	497	494
Interest on subordinated debt held by unconsolidated subsidiary trusts	722	627	1,416	1,241
Total interest expense	2,804	2,652	5,679	5,266
Net interest income	68,306	61,228	135,187	121,068
Provision for loan losses	2,305	591	3,646	1,214
Net interest income after provision for loan losses	66,001	60,637	131,541	119,854
Noninterest revenues:
Deposit service fees	15,008	13,213	28,742	25,683
Other banking services	1,597	799	3,176	1,854
Employee benefit services	11,671	11,322	23,682	22,397
Insurance revenues	5,797	325	11,638	724
Wealth management services	4,699	4,060	9,815	8,107
Total noninterest revenues	38,772	29,719	77,053	58,765
Noninterest expenses:
Salaries and employee benefits	37,950	31,010	77,088	62,039
Occupancy and equipment	7,409	6,844	15,072	14,239
Data processing and communications	8,732	7,473	17,142	14,463
Amortization of intangible assets	1,403	880	2,845	1,799
Legal and professional fees	1,857	1,642	4,374	3,388
Office supplies and postage	1,846	1,517	3,623	3,097
Business development and marketing	2,149	2,258	4,163	3,822
FDIC insurance premiums	1,090	963	2,192	1,952
Acquisition expenses	263	361	340	756
Other expenses	3,657	3,100	7,186	6,441
Total noninterest expenses	66,356	56,048	134,025	111,996
Income before income taxes	38,417	34,308	74,569	66,623
Income taxes	12,560	10,468	24,309	20,486
Net income	$ 25,857	$ 23,840	$ 50,260	$ 46,137
Basic earnings per share (in dollars per share)	$ 0.58	$ 0.58	$ 1.14	$ 1.13
Diluted earnings per share (in dollars per share)	0.58	0.58	1.13	1.12
Cash dividends declared per share (in dollars per share)	$ 0.31	$ 0.30	$ 0.62	$ 0.60