Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 8,132
Common Shares of Beneficial Interest - par value, $.03 per share; shares authorized: 275,000; shares issued and outstanding: 128,673 in 2019 and 128,333 in 2018
Common Shares of Beneficial Interest; par value (dollars per share)	$ 0.03	$ 0.03
Common Shares of Beneficial Interest - shares authorized (shares)	275,000	275,000
Common Shares of Beneficial Interest - shares issued (shares)	128,103	128,702
Common Shares of Beneficial Interest - shares outstanding (shares)	128,103	128,702

The valuation allowance as of the balance sheet date to reduce the gross amount of receivables to estimated net realizable value, which would be presented in parentheses on the face of the balance sheet.

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Face amount or stated value per share of common stock.

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