CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	2	2
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Special Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Special Stock, Shares Authorized	1	1
Special Stock, Shares Issued	1	1
Special Stock, Shares Outstanding	1	1
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	79,999,997	79,999,997
Common Stock, Shares, Issued	37,156,068	36,803,218
Common Stock, Shares, Outstanding	31,644,345	31,451,796
Treasury Stock, Shares	5,511,723	5,351,422
Blank Check Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	40,000,000	40,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0