Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowances	$ 3,508	$ 5,738
Preferred stock, shares, issued (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares, authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares, authorized (in shares)	100,000,000	100,000,000
Common Stock, shares, issued (in shares)	48,760,000	47,577,000
Common stock, shares, outstanding (in shares)	39,615,000	38,432,000
Treasury stock, shares (in shares)	9,145,000	9,145,000

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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