Regulatory and Legal Developments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014 Plaintiff
Legal Proceedings And Contingencies [Line Items]
Number Of Plaintiffs	8
Number of additional groups of plaintiffs	3
Number of plaintiffs in each group	10
Trial Date One
Legal Proceedings And Contingencies [Line Items]
Additional trials starting date	2014-07
Trial Date Two
Legal Proceedings And Contingencies [Line Items]
Additional trials starting date	2014-10
Trial Date Three
Legal Proceedings And Contingencies [Line Items]
Additional trials starting date	2015-01