Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Receivables, allowance	$ 15,182	$ 11,308
Intangible assets, accumulated amortization	$ 82,406	$ 54,184
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	30,184,330	29,953,041