Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Receivables, allowance	$ 12,709	$ 7,835
Intangible assets, accumulated amortization	$ 50,143	$ 37,309
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value (in usd per share)	$ 0.30	$ 0.30
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	29,841,993	29,784,734