Condensed Consolidated Statements of Earnings and Comprehensive 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:
Loans and leases, including fees	$ 50,257	$ 45,322	$ 96,027	$ 90,864
Investment securities:
Investment securities available-for-sale	12,018	17,503	24,817	35,437
Investment securities held-to-maturity	4,743	36	10,091	74
Total investment income	16,761	17,539	34,908	35,511
Dividends from FHLB stock	439	1,414	807	1,883
Federal funds sold	383	187	488	329
Interest-earning deposits with other institutions	175	53	285	108
Total interest income	68,015	64,515	132,515	128,695
Interest expense:
Deposits	1,582	1,307	3,019	2,600
Borrowings	345	342	768	2,115
Junior subordinated debentures	132	108	256	213
Total interest expense	2,059	1,757	4,043	4,928
Net interest income before recapture of provision for loan losses	65,956	62,758	128,472	123,767
Recapture of provision for loan losses	0	(2,000)	0	(2,000)
Net interest income after recapture of provision for loan losses	65,956	64,758	128,472	125,767
Noninterest income:
Service charges on deposit accounts	3,822	3,952	7,569	7,913
Trust and investment services	2,508	2,181	4,711	4,332
Bankcard services	784	842	1,339	1,575
BOLI income	752	808	1,299	1,457
Gain on sale of loans	0	0	1,101	0
Other	1,408	562	1,938	1,079
Total noninterest income	9,274	8,345	17,957	16,356
Noninterest expense:
Salaries and employee benefits	21,558	19,648	42,811	38,943
Occupancy and equipment	4,125	3,713	7,838	7,365
Professional services	1,188	1,527	2,554	2,680
Software licenses and maintenance	1,065	993	1,974	2,023
Promotion	1,192	1,201	2,619	2,528
Recapture of provision for unfunded loan commitments	0	0	0	(500)
Debt termination expense	16	0	16	13,870
Acquisition related expenses	355	0	1,204	0
Other	4,939	4,451	9,786	9,096
Total noninterest expense	34,438	31,533	68,802	76,005
Earnings before income taxes	40,792	41,570	77,627	66,118
Income taxes	15,278	14,757	28,722	23,472
Net earnings	25,514	26,813	48,905	42,646
Other comprehensive income (loss):
Unrealized gain (loss) on securities arising during the period, before tax	7,493	(32,968)	34,763	(12,698)
Less: Income tax (expense) benefit related to items of other comprehensive income	(3,147)	13,846	(14,600)	5,332
Net change, After-tax	4,346	(19,122)	20,163	(7,366)
Comprehensive income	$ 29,860	$ 7,691	$ 69,068	$ 35,280
Basic earnings per common share	$ 0.23	$ 0.25	$ 0.46	$ 0.40
Diluted earnings per common share	0.23	0.25	0.45	0.40
Cash dividends declared per common share	$ 0.12	$ 0.12	$ 0.24	$ 0.24