Summary of Activity for Each of Company's Other Investments (Detail) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			$ 156,766			$ 156,766
Cash distributions received	[1]	$ (5,323)		$ (3,932)		(19,665)	$ (16,255)
Equity in income		8,439		6,414		18,843	15,050
Other comprehensive income (loss) in equity method investments		(22)	(71)	$ (116)	$ 136	(93)	$ 20
Investments, ending balance		164,176				164,176
Other Affiliates
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			156,766			156,766
Cash distributions received						(6,218)
Equity in income						13,831
Other comprehensive income (loss) in equity method investments						(93)
Other						(110)
Investments, ending balance		164,176				164,176
Other Affiliates | Digital Cinema Implementation Partners
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			125,252			125,252
Cash distributions received						(5,218)
Equity in income						11,167
Other comprehensive income (loss) in equity method investments						(93)
Other						0
Investments, ending balance		131,108				131,108
Other Affiliates | AC JV, LLC
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			5,266			5,266
Cash distributions received						(1,000)
Equity in income						2,150
Other comprehensive income (loss) in equity method investments						0
Other						0
Investments, ending balance		6,416				6,416
Other Affiliates | Digital Cinema Distribution Coalition
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			2,255			2,255
Cash distributions received						0
Equity in income						532
Other comprehensive income (loss) in equity method investments						0
Other						0
Investments, ending balance		2,787				2,787
Other Affiliates | FE Concepts, LLC
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			19,918			19,918
Cash distributions received						0
Equity in income						(18)
Other comprehensive income (loss) in equity method investments						0
Other						0
Investments, ending balance		19,900				19,900
Other Affiliates | Other Investments
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance			$ 4,075			4,075
Cash distributions received						0
Equity in income						0
Other comprehensive income (loss) in equity method investments						0
Other						(110)
Investments, ending balance		$ 3,965				$ 3,965

[1] Includes cash distributions received from equity investees that were recorded as a reduction of the respective investment balances (see Notes 8 and 9).  These distributions are reported entirely within the U.S. operating segment.