Schedule II Valuation of Qualifying Accounts and Reserves

12 Months Ended

Dec. 31, 2017

Schedule II Valuation and Qualifying Accounts and Reserves [Abstract]

Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (In Thousands, Except Per Share Data)
			Column C
Column A	Column B		Charges To				Column D		Column E
	Balance At		Cost						Balance
	Beginning		And		Other				At End
Description	of Period		Expense		Accounts		Deductions		of Period
Allowance for doubtful accounts:
Year ended December 31, 2017	$	1,475	$	—	$	—	$	—	$	1,475
Year ended December 31, 2016	1,475		—		—		—		1,475
Year ended December 31, 2015	1,262		318		—		105		1,475

See accompanying Report of Independent Registered Public Accounting Firm.