Legal and Regulatory Proceedings - Additional Information (Detail) (USD $)	12 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2008 number	Dec. 31, 2013	Dec. 31, 2013 SEC Investigation
Commitments and Contingencies Disclosure [Line Items]
Number of putative securities class action complaints		5
Number of cases that have been consolidated		5
Number of additional lawsuit filed		2
Number of alleging violations of ERISA that were dismissed		2
Class Settlement Escrow	$ 46,000,000
Non Class Action Escrow	4,000,000
Payments for Legal Settlements	16,000,000			6,500,000
Civil Money Penalty				100,000
Amount in excess of amounts reserved			$ 113,000,000