Fair Value Of Financial Instruments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) agreement	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) agreement	Jun. 30, 2018 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other comprehensive loss	$ (399)	$ (77)	$ (608)	$ 390
Accumulated other comprehensive loss
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other comprehensive loss	(399)	$ (77)	(608)	$ 390
Accumulated other comprehensive loss | One of our equity method investees
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other comprehensive loss	$ 400		$ 600
Fair Value, recurring | Interest rate swap | One of our equity method investees
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Number of interest rate swap agreements | agreement	2		2