Divestiture - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended		0 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Transition Service Agreement [Member]	Jun. 30, 2014 Minimum [Member]	Jun. 30, 2014 Maximum [Member]	Jun. 28, 2013 NASDAQ OMX [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase price in cash			$ 0	$ 747,675,000				$ 750,000,000
Contingent consideration earn-out period								15 years
Consolidated gross revenue target								25,000,000
Aggregate number of shares to be issued								14,883,705
Services agreement period						12 months	18 months
Proceeds from the sale to the transition services agreement	2,900,000		2,900,000
Other revenues	$ 3,530,000	$ 1,174,000	$ 11,726,000	$ 2,005,000	$ 750,000