Significant Accounting Policies (Impact Of Adopting Leasing Standard On Balance Sheet) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating leases
Leased right-of-use assets, net	$ 41,343
Prepaid expenses	2,360		$ 1,650
Accrued liabilities	15,043		15,664
Operating lease liabilities, net of current portion	39,703
Taxes payable and other	2,548		3,381
Retained earnings	76,327		76,056
Non-controlling interests	7,393		7,062
Finance leases
Property and equipment, net	201,097		187,017
Leased right-of-use assets, net	1,453
Current portion of long-term debt	17,841		17,482
Current portion of finance lease liabilities	281
Long-term debt, less current portion and deferred financing costs	54,216		42,041
Finance lease liabilities, net of current portion	$ 952
Prior To Adoption [Member]
Operating leases
Prepaid expenses			1,650
Accrued liabilities			15,664
Taxes payable and other			3,381
Retained earnings			76,056
Non-controlling interests			7,062
Finance leases
Property and equipment, net			187,017
Current portion of long-term debt			17,482
Long-term debt, less current portion and deferred financing costs			$ 42,041
Post Adoption [Member]
Operating leases
Leased right-of-use assets, net		$ 38,276
Prepaid expenses		1,514
Accrued liabilities		15,025
Operating lease liabilities, net of current portion		40,410
Taxes payable and other		2,031
Retained earnings		75,824
Non-controlling interests		7,013
Finance leases
Property and equipment, net		186,655
Leased right-of-use assets, net		362
Current portion of long-term debt		17,359
Current portion of finance lease liabilities		123
Long-term debt, less current portion and deferred financing costs		41,731
Finance lease liabilities, net of current portion		310
Accounting Standards Update 2016-02 [Member] | Changes Related To Adoption [Member]
Operating leases
Leased right-of-use assets, net		38,276
Prepaid expenses		(136)
Accrued liabilities		(639)
Operating lease liabilities, net of current portion		40,410
Taxes payable and other		(1,350)
Retained earnings		(232)
Non-controlling interests		(49)
Finance leases
Property and equipment, net		(362)
Leased right-of-use assets, net		362
Current portion of long-term debt		(123)
Current portion of finance lease liabilities		123
Long-term debt, less current portion and deferred financing costs		(310)
Finance lease liabilities, net of current portion		$ 310