Income Taxes Qualified Affordable Housing Projects and Other Tax Credit Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Affordable housing tax credit investments, net	$ 152,203	$ 153,351
Other tax credit investments, net	59,224	64,354
Total TCIs, net	211,427	217,705
Other tax credit liabilities	31,562	16,684
Other tax credit liabilities	49,491	55,105
Total unfunded tax credit commitments and liabilities	81,053	71,789
Affordable housing tax credits and other tax benefits	(28,777)	(30,642)	$ (30,721)
Other tax credit investment credits and tax benefits	(4,163)	(4,542)	(6,385)
Amortization of affordable housing investments, net of tax benefit	20,429	22,184	21,569
Deferred tax expense	921	954	1,341
Total reduction in income tax expense	(11,590)	(12,046)	(14,196)
Affordable housing tax credits investment	4,087	3,344	3,355
Other tax credit investment amortization	2,039	2,677	8,094
Total amortization of TCIs	$ 6,126	$ 6,021	$ 11,449