Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Real estate secured loans	$ 223,361	$ 215,231	$ 189,896
Commercial loans	82,540	79,371	72,907
Consumer loans	18,579	19,906	20,301
Available for sale debt securities and Federal Home Loan Bank Stock	31,842	30,981	26,445
Held to maturity debt securities	12,424	12,606	13,027
Deposits, federal funds sold and other short-term investments	2,724	1,734	1,270
Total interest income	371,470	359,829	323,846
Interest expense:
Deposits	45,494	30,693	19,441
Borrowed funds	28,003	28,460	26,203
Total interest expense	73,497	59,153	45,644
Net interest income	297,973	300,676	278,202
Provision for loan losses	13,100	23,700	5,600
Net interest income after provision for loan losses	284,873	276,976	272,602
Non-interest income:
Fees	28,321	28,084	27,218
Wealth management income	22,503	17,957	17,604
Bank-owned life insurance	6,297	5,514	6,693
Net gain on securities transactions	72	2,221	57
Other income	6,601	4,900	4,125
Total non-interest income	63,794	58,676	55,697
Non-interest expense:
Compensation and employee benefits	116,849	111,496	109,353
Net occupancy expense	25,895	25,056	25,290
Data processing expense	16,836	14,664	13,922
FDIC Insurance	1,316	3,482	3,887
Advertising and promotion expense	4,115	3,836	3,904
Amortization of intangibles	2,740	2,127	2,670
Other operating expenses	33,828	31,074	28,796
Total non-interest expenses	201,579	191,735	187,822
Income before income tax expense	147,088	143,917	140,477
Income tax expense	34,455	25,530	46,528
Net income	$ 112,633	$ 118,387	$ 93,949
Basic earnings per share (in dollars per share)	$ 1.74	$ 1.82	$ 1.46
Average basic shares outstanding (in shares)	64,604,224	64,942,886	64,384,851
Diluted earnings per share (in dollars per share)	$ 1.74	$ 1.82	$ 1.45
Average diluted shares outstanding (in shares)	64,734,591	65,103,097	64,579,222