Summary of Activity for Each of Company's Other Investments (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				$ 120,045
Cash distributions received	[1]	$ (3,932)	$ (2,870)	(16,255)	$ (14,919)
Equity in earnings		6,414	5,805	15,050	15,865
Equity in other comprehensive income		(116)	$ (95)	20	$ 103
Investments, ending balance		145,081		145,081
Other Affiliates
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				120,045
Cash contributions made				20,739
Cash distributions received				(5,201)
Equity in earnings				10,539
Equity in other comprehensive income				20
Other				(1,061)
Investments, ending balance		145,081		145,081
Other Affiliates | Digital Cinema Implementation Partners
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				106,215
Cash contributions made				739
Cash distributions received				(5,201)
Equity in earnings				9,727
Equity in other comprehensive income				20
Other				0
Investments, ending balance		111,500		111,500
Other Affiliates | AC JV, LLC
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				5,916
Cash contributions made				0
Cash distributions received				0
Equity in earnings				408
Equity in other comprehensive income				0
Other				0
Investments, ending balance		6,324		6,324
Other Affiliates | Digital Cinema Distribution Coalition
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				3,598
Cash contributions made				0
Cash distributions received				0
Equity in earnings				481
Equity in other comprehensive income				0
Other				(1,168)
Investments, ending balance		2,911		2,911
Other Affiliates | FE Concepts, LLC
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				104
Cash contributions made				20,000
Cash distributions received				0
Equity in earnings				(77)
Equity in other comprehensive income				0
Other				(104)
Investments, ending balance		19,923		19,923
Other Affiliates | Other Investments
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance				4,212
Cash contributions made				0
Cash distributions received				0
Equity in earnings				0
Equity in other comprehensive income				0
Other				211
Investments, ending balance		$ 4,423		$ 4,423

[1] Includes cash distributions received from equity investees that were recorded as a reduction of the respective investment balances (see Notes 7 and 8). These distributions are reported entirely within the U.S. operating segment.