Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 5,233	$ 5,132
Common stock, par value	$ 0	$ 0
Common Stock, Shares Authorized	200,000,000	200,000,000
Common stock, shares outstanding	65,688,356	65,494,333