Schedule II - Valuation and Qualifying Accounts Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts:
The roll forward of valuation accounts were as follows:
Balance at beginning of period	$ 543	$ 733	$ 828
Charged to costs and expenses	361	353	715
Deductions	(450)	(543)	(810)
Balance at end of period	454	543	733
Valuation allowance for deferred tax assets:
The roll forward of valuation accounts were as follows:
Balance at beginning of period	36,516	36,675	35,834
Charged to costs and expenses	(1,100)	(159)	841
Deductions	0	0	0
Balance at end of period	$ 35,416	$ 36,516	$ 36,675