Condensed Consolidated Balance Sheet (Parenthetical) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 2,692,000	$ 2,622,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	63,964,072	63,390,744
Common stock, shares outstanding (in shares)	54,037,447	54,088,188
Treasury stock at cost (in shares)	9,926,626	9,302,556