Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for credit loss	$ 5,344	$ 4,860
Cumulative preferred nonvoting stock (as a percent)	4.50%	4.50%
Preferred stock, par value (dollars per share)	$ 50,000	$ 50,000
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	180,000,000	180,000,000
Common stock, shares issued (in shares)	62,081,391	62,081,391
Common stock, shares outstanding (in shares)	39,067,902	38,841,194