Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Receivables: net of allowance for doubtful accounts	$ 830	$ 730
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	68,000,000	68,000,000
Common stock, shares outstanding (in shares)	47,964,915	47,875,139