Summary of Revenues and Pre-Tax Loss Generated by Angel Dot Com Business In Addition to Pre-Tax Gain on Sale Recorded (Detail) (Angel.Com, USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Angel.Com
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Angel.com revenues	$ 0	$ 6,320	$ 28,882
Angel.com pre-tax loss	0	986	2,976
MicroStrategy pre-tax gain on sale	$ 0	$ 94,925	$ 0

Amount of gain (loss), before tax expense or benefit and not previously recognized, resulting from the sale of a business component.

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Amount of operating income or loss attributable to the disposal group, including a component of the entity (discontinued operation), during the reporting period.

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