Schedule II - Valuation and Qualifying Accounts (Details) - SEC Schedule, 12-09, Allowance, Credit Loss $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance At Beginning of Year	$ 1,607
Additions Charged Against Operations	(811)
Uncollectible Accounts Written-Off	(289)
Balance at End of Year	$ 507