Summary of Activity for Each of Investments (Detail) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
		Dec. 31, 2013	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					$ 94,973
Equity in income of affiliates			$ 12,390	$ 11,047	24,597	$ 20,372
Equity in comprehensive loss			(7)	$ (72)	(183)	$ (3,010)
Investments, ending balance			100,621		100,621
Other Affiliates
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					94,973
Cash contributions					1,706
Equity in income of affiliates					16,937
Equity in comprehensive loss					(183)
Sale of investment	[1]				(12,900)
Other					88
Investments, ending balance			100,621		100,621
Digital Cinema Implementation Partners | Other Affiliates
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					71,579
Cash contributions					706
Equity in income of affiliates					16,006
Equity in comprehensive loss					(183)
Investments, ending balance			88,108		88,108
RealD | Other Affiliates
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					12,900
Sale of investment	[1]				(12,900)
AC JV, LLC | Other Affiliates
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					7,269
Cash contributions		$ 268
Equity in income of affiliates					120
Investments, ending balance			7,389		7,389
Digital Cinema Distribution Coalition | Other Affiliates
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					2,562
Equity in income of affiliates					811
Investments, ending balance			3,373		3,373
Other Investment | Other Affiliates
Schedule of Equity Method Investments [Line Items]
Investments, beginning balance					663
Cash contributions					1,000
Other					88
Investments, ending balance			$ 1,751		$ 1,751

[1] See further discussion of the sale of the investment held by the Company under RealD, Inc. below.