Divestiture - Additional Information (Detail) (USD $)	12 Months Ended						0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Transition Service Agreement [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]	Jun. 28, 2013 NASDAQ OMX [Member]	Dec. 31, 2013 NASDAQ OMX [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase price in cash	$ 750,000,000						$ 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
Fees paid related to divestiture	7,400,000
Services agreement period					12 months	18 months
Proceeds from the sale to the transition services agreement	(2,943,000)
Tax expense on the gain on divestiture	172,400,000
Other revenues	$ 44,643,000	$ 4,495,000	$ 4,174,000	$ 1,500,000				$ 39,500,000