Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Doubtful accounts written off (net)	$ (177)
Reclassified to assets held for sale (see Note 3)	(152)
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance, Beginning Balance	5,010	$ 5,143	$ 3,992
Provision charged to income	1,347	363	1,512
Doubtful accounts written off (net)	(960)	(416)	(297)
Other adjustments	(48)	(80)	(64)
Allowance, Ending Balance	$ 5,197	$ 5,010	$ 5,143