Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Trade receivables, allowance for doubtful accounts	$ 4,732	$ 5,344
Common Stock, No Par Value	$ 0	$ 0
Preferred Stock
Percentage of cumulative preferred stock (percent)	4.50%
Preferred stock, par value (dollars per share)	$ 50,000	$ 50,000