Summary Of Major Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
Property, Plant and Equipment [Line Items]
Interest costs capitalized	$ 1,400		$ 1,800
Goodwill, Impairment loss		$ 76,000		$ 68,000
Cumulative effect of new accounting principle in period of adoption					$ (5,860)	$ (537)
Lease assets	180,645				184,648
Lease, liability	$ 191,823				190,508
Lease, term of contract	20 years
Minimum [Member]
Property, Plant and Equipment [Line Items]
Threshold for consolidation, percentage	50.00%
Equity method investment, threshold for consolidation, percentage	20.00%
Maximum [Member]
Property, Plant and Equipment [Line Items]
Equity method investment, threshold for consolidation, percentage	50.00%
Retained Earnings [Member]
Property, Plant and Equipment [Line Items]
Cumulative effect of new accounting principle in period of adoption					(5,860)	(537)
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Property, Plant and Equipment [Line Items]
Cumulative effect of new accounting principle in period of adoption						$ 537
Accounting Standards Update 2016-02 [Member] | Retained Earnings [Member]
Property, Plant and Equipment [Line Items]
Cumulative effect of new accounting principle in period of adoption					$ 5,900