Investment in Marketable Securities - RealD, Inc. - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Number of options to purchase common stock	1,222,780
Exercise price of options, shares	$ 0.00667
Number of shares owned in RealD	1,222,780
Estimated fair value of company owned shares in RealD	$ 8,559	$ 13,707
Unrealized holding loss	$ 5,148

The aggregate net change in the difference between the fair value and the carrying value, or in the comparative fair values, of marketable securities categorized as trading held at each balance sheet date, that was included in earnings for the period, which may have arisen from (a) securities classified as trading, (b) the unrealized holding gain (loss) on held-to-maturity securities transferred to the trading security category, and (c) the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) on available-for-sale securities transferred to trading securities during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27405-111563

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration