Tax Credit Investments - Income Statement Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Components of Income Tax Expense:
Affordable housing tax credits and other tax benefits	$ 897	$ 1,234
Other tax credit investment credits and tax benefits	2,685	1,300
Total reduction in income tax expense	3,582	2,534
Non-Interest Expenses
Amortization of Tax Credit Investments:
Affordable housing tax credit investment losses	543	554
Affordable housing tax credit investment impairment losses	341	418
Other tax credit investment losses	173	544
Other tax credit investment impairment losses	1,687	1,712
Total amortization of tax credit investments recorded in non-interest expense	$ 2,744	$ 3,228