Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance, Beginning	$ 15,549	$ 14,234	$ 14,435
Valuation Allowances and Reserves, Charged to Cost and Expense	1,167	1,403	1,087
Valuation Allowances and Reserves, Charged to Other Accounts	678	1,005	760
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	569	1,093	528
Valuation Allowances and Reserves, Balance, Ending	15,469	15,549	14,234
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance, Beginning	12,857	10,730	25,435
Valuation Allowances and Reserves, Charged to Cost and Expense	0	9,513	0
Valuation Allowances and Reserves, Charged to Other Accounts	3,023	72,170	0
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	796	79,556	14,705
Valuation Allowances and Reserves, Balance, Ending	$ 15,084	$ 12,857	$ 10,730