Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 2,489	$ 1,451
Common stock - par value (in dollars per share)	$ 0.01	$ 0.01
Common stock - shares authorized (in shares)	180,000,000	180,000,000
Common stock - issued (in shares)	13,627,000	13,579,000
Treasury stock (in shares)	1,386,000	1,371,000