Related Parties (Narrative) (Details) - USD ($)					12 Months Ended
		Aug. 31, 2016	Jan. 01, 2015	Jun. 28, 2007	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2012	Feb. 28, 2015
Related Party Transaction [Line Items]
Total operating property					$ 264,724,000		$ 211,886,000	[1]
Current capital lease liability	[2]				5,900,000		5,900,000
Contributions from noncontrolling stockholders					193,000		268,000		$ 17,000
Renovation amount					153,232,000		122,863,000
Contractual facility					271,732,000		266,134,000
Capital call							506,000
US Cinema 1, 2, 3 Term Loan And Line Of Credit [Member]
Related Party Transaction [Line Items]
Contractual facility		$ 15,000,000			19,500,000	[3]	19,901,000	[4]
Cinemas 1, 2, 3 [Member]
Related Party Transaction [Line Items]
Improvement fee					0		0		0
Management fee									177,000
Incremental positive cash flow percentage			100.00%
Average annual positive cash flow period			3 years
Annual cash-on-cash return percent			15.00%
Sutton Hill Capital, LLC [Member]
Related Party Transaction [Line Items]
Related party expense					$ 590,000		590,000		590,000
Lease term					10 years
Lease expiration date					Jun. 30, 2020
Purchase option					$ 5,900,000
Total operating property					4,700,000
Current capital lease liability					$ 5,900,000
Payment to acquire interest in special purpose entity				$ 3,000,000
Debt amount				26,900,000
Due from related party				$ 2,900,000
Renovation amount											$ 750,000
Capital call							169,000
Guarantee and indemnity percentage					25.00%
Sutton Hill Capital, LLC [Member] | Cinemas 1, 2, 3 [Member]
Related Party Transaction [Line Items]
Percent of management fee equal to SHP's gross income					5.00%
Sutton Hill Capital's Interest In Sutton Hill Properties [Member]
Related Party Transaction [Line Items]
Special purpose entity purchase option, percentage					25.00%
OBI Management [Member]
Related Party Transaction [Line Items]
Estimated related party expense							79,000		589,000
Historical related party fees paid as percentage of cash flow received from certain theaters					21.00%
James Cotter And Michael Forman [Member]
Related Party Transaction [Line Items]
Ownership percentage in live theater play investment					5.00%
Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Contributions from noncontrolling stockholders										$ 2,500,000
Bonus contributed to acquire land										$ 255,000
Noncontrolling interests										50.00%
Cinema Ground Lease [Member]
Related Party Transaction [Line Items]
Lease expiration date					Jun. 01, 2031
86th Street Cinema [Member]
Related Party Transaction [Line Items]
Management fee					$ 141,000		$ 150,000		$ 151,000
Minimum [Member]
Related Party Transaction [Line Items]
Lease term					1 year
Minimum [Member] | 2010 Stock Incentive Plan [Member]
Related Party Transaction [Line Items]
Vesting period of stock options and RSU					0 years
Minimum [Member] | Sutton Hill Capital, LLC [Member]
Related Party Transaction [Line Items]
Purchase option					$ 100,000
Australian Country Cinemas, Pty Ltd [Member]
Related Party Transaction [Line Items]
Noncontrolling interests					25.00%
Sutton Hill Properties, LLC [Member]
Related Party Transaction [Line Items]
Noncontrolling interests					25.00%
Sutton Hill Properties, LLC [Member] | US Cinema 1, 2, 3 Term Loan And Line Of Credit [Member]
Related Party Transaction [Line Items]
Contractual facility		$ 15,000,000

[1] Certain prior year balances have been reclassified to conform to the 2017 presentation (see Note 2 - Summary of Significant Accounting Policies - Reclassifications).

[2] Represents the lease liability of the option associated with the ground lease purchase of the Village East Cinema. See below for more information.

[3] In June 2017 we received $1.5M in additional financing on our new U.S. Corporate Headquarters with Citizens Asset Finance, Inc. due to the reappraisal of the property.

[4] The loan for our Minetta & Orpheum Theatres was obtained from Santander Bank. The term loan for our Cinema 1,2,3 Theatre was refinanced during the third quarter of 2016 with Valley National Bank. The term loan, which is collateralized by our new U.S Corporate Headquarters office building, was obtained with Citizens Asset Finance, Inc. In December 2016, we successfully negotiated the construction financing for our Union Square redevelopment project, $8.0 million of which was advanced from the total construction loan limit of $57.5 million.