Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts related to receivables	$ 281	$ 264
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred shares, shares authorized (in shares)	100,000,000	100,000,000
Preferred shares, shares issued (in shares)
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, shares authorized (in shares)	500,000,000	500,000,000
Common shares, shares issued (in shares)	46,571,005	46,525,652
Common shares, shares outstanding (in shares)	46,571,005	46,525,652

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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