Organization and Basis of Presentation - Additional Information (Detail) (USD $)	3 Months Ended			6 Months Ended		9 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013 Segment	Mar. 31, 2012 Segment	Jun. 30, 2013 Segment	Jun. 30, 2012 Segment	Dec. 31, 2012 Segment	Jun. 30, 2013 Class A Common Stock [Member]	Jun. 30, 2013 Class A Common Stock [Member]	Jun. 30, 2013 Global Partnership Restructuring Program [Member]	Jun. 30, 2013 Global Partnership Restructuring Program [Member]	Jun. 30, 2013 Global Partnership Restructuring Program [Member] Class A Common Stock [Member]	Jun. 30, 2013 Global Partnership Restructuring Program [Member] Class A Common Stock [Member]	Jun. 30, 2013 Maximum [Member]	Jun. 30, 2013 Minimum [Member]	Jun. 28, 2013 NASDAQ OMX [Member]	Jun. 30, 2013 NASDAQ OMX [Member]
Description Of Business [Line Items]
Number of reportable segments		2	1	2	2	2
Proceeds from divestiture				$ 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	14,883,705
Redemption of partner units	77,400,000								77,400,000	77,400,000
Common stock granted and expected to issue							45,200,000	45,200,000			45,200,000	45,200,000
Common stock issue,restricted shares							39,100,000	39,100,000			39,100,000	39,100,000
Restricted shares saleable period													10 years	5 years
Company reducing fully diluted share	32,200,000
Non-cash, non-dilutive compensation charges	464,600,000			334,641,000	61,943,000
Gain related to the NASDAQ OMX transaction	$ 723,147,000			$ 723,147,000