Schedule II - Consolidated Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - 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]
Balance at beginning of period	$ 8,325	$ 9,156	$ 7,706
Charged to costs and expenses	4,678	542	3,000
Charged to other accounts	0	0	0
Deductions	(222)	(1,373)	(1,550)
Balance at end of period	$ 12,781	$ 8,325	$ 9,156