CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Shares Outstanding	0	0
Current assets
Allowance for doubtful accounts	$ 758	$ 647
Stockholders equity
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	240,000,000	240,000,000
Common stock, shares issued	69,254,000	87,522,000
Common stock, shares outstanding	54,047,000	53,396,000
Treasury Stock, Shares	15,207,000	34,126,000