Tax Credit Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Affordable housing tax credit investment, net	$ 145,415		$ 145,415		$ 153,351
Other tax credit investments, net	70,379		70,379		64,354
Total TCIs, net	215,794		215,794		217,705
Unfunded affordable housing tax credit commitments	22,591		22,591		16,684
Other tax credit liabilities	60,585		60,585		55,105
Total unfunded tax credit commitments and liabilities	83,176		83,176		$ 71,789
Affordable housing tax credits and other tax benefits	(7,290)	$ (7,852)	(21,678)	$ (23,002)
Other tax credit investment credits and tax benefits	(1,240)	(1,136)	(3,122)	(3,407)
Amortization of affordable housing investments, net of tax benefit	5,024	5,649	15,071	16,638
Deferred tax expense	275	238	691	715
Total net reduction in income tax expense	(3,231)	(3,101)	(9,038)	(9,056)
Affordable housing tax credits investment	1,021	863	3,065	2,508
Other tax credit investment amortization	673	670	1,529	2,008
Total amortization of TCIs	$ 1,694	$ 1,533	$ 4,594	$ 4,516