Tax Credit Investments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Affordable housing tax credit investment, net	$ 161,986		$ 161,986		$ 170,401
Other tax credit investments, net	72,786		72,786		72,584
Total TCIs, net	234,772		234,772		242,985
Unfunded affordable housing tax credit commitments	18,542		18,542		23,196
Other tax credit investment liabilities	61,483		61,483		59,823
Total unfunded tax credit investment commitments and liabilities	80,025		80,025		$ 83,019
Affordable housing tax credits and other tax benefits	(7,575,000)	$ (7,543,000)	(15,150,000)	$ (15,087,000)
Other tax credit investment credits and tax benefits	(1,135,000)	(1,597,000)	(2,271,000)	(3,193,000)
Amortization of affordable housing investments, net of tax benefit	5,494,000	5,319,000	10,989,000	10,917,000
Deferred tax expense	239,000	336,000	477,000	671,000
Total reduction in income tax expense	(2,977,000)	(3,485,000)	(5,955,000)	(6,692,000)
Affordable housing tax credits investment	823,000	839,000	1,645,000	1,678,000
Other tax credit investment amortization	669,000	798,000	1,338,000	1,596,000
Total amortization of TCIs	$ 1,492,000	$ 1,637,000	$ 2,983,000	$ 3,274,000