SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 6,991	$ 6,899
Additions Charged to Expense	1,664	1,273
Acquired from Acquisitions	0	0
Deductions	584	1,181
Balance at End of Year	8,071	6,991
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	241,789	381,586
Additions Charged to Expense	8,190	3,004
Acquired from Acquisitions	0	0
Deductions	124,109	142,801
Balance at End of Year	$ 125,870	$ 241,789