Litigation and Regulatory Matters - Additional Information (Detail) - USD ($)		1 Months Ended
	Apr. 13, 2016	Apr. 30, 2016	Mar. 31, 2016
Loss Contingencies [Line Items]
Estimate of possible loss for all litigation matters			$ 3,100,000,000
Subsequent Event [Member] | Telephone Consumer Protection Act Litigation [Member]
Loss Contingencies [Line Items]
Damages sought, each violation (at least)		$ 500
Subsequent Event [Member] | Credit Monitoring Product [Member]
Loss Contingencies [Line Items]
Civil penalty assessed	$ 35,000,000