Schedule II (Details) - SEC Schedule, 12-09, Allowance for Doubtful Accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019	Dec. 31, 2016
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	$ 0	$ 7,594	$ 6,285	$ 0	$ 4,526
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense	0	3,298	3,807
SEC Schedule, 12-09, Valuation Allowances and Reserves, Increase (Decrease) Adjustment	0	0	0
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	$ 0	$ 1,989	$ 2,048