Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Allowance for doubtful accounts	$ 12,335	$ 10,422
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	95,000,000	95,000,000
Common stock, shares issued	47,585,935	48,082,800
Common stock, shares outstanding	47,585,935	47,482,800
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Treasury Stock, Shares	0	600,000
Series A Preferred Stock [Member]
Preferred stock, shares authorized	6,000	6,000
Series B Preferred Stock [Member]
Preferred stock, shares authorized	20,000	20,000