Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 Class_Member	Dec. 31, 2013
Commitments And Contingencies [Line Items]
License bonds outstanding amount	$ 2.3	$ 2.4
Number of class member opted out of settlement before finalization	18
Damages sought amount	87
Guarantor [Member]
Commitments And Contingencies [Line Items]
Letters of credit outstanding	1.9	1.9
Letters of Credit [Member]
Commitments And Contingencies [Line Items]
Letters of credit outstanding	2.5	2.5
Ashkenazi [Member]
Commitments And Contingencies [Line Items]
Damages sought amount	92
Victims Recovery [Member]
Commitments And Contingencies [Line Items]
Damages sought amount	53
Marsh, Facciola, Rader, and ML Liquidating Trust [Member]
Commitments And Contingencies [Line Items]
Damages sought amount	200
Rader [Member]
Commitments And Contingencies [Line Items]
Damages sought amount	$ 15