Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ / shares in Thousands	Mar. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts	$ 52,912	$ 53,708
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares issued (in shares)	131,124,989	131,124,989
Common stock, shares outstanding (in shares)	131,124,989	131,124,989

Amount of allowance for credit loss on accounts receivable, classified as current.

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