Litigation and Regulatory Matters - Additional Information (Details) - USD ($)	1 Months Ended	36 Months Ended
	Apr. 30, 2016	Dec. 31, 2007	Mar. 31, 2016	Mar. 31, 2015
Loss Contingencies [Line Items]
Estimate of loss			$ 125,000,000
Mortgage Securitization Activity Related Litigation [Member] | HSBC Securities [Member]
Loss Contingencies [Line Items]
Mortgage Securitization Loan Purchased And Sold		$ 24,000,000,000
Mortgage Securitization Outstanding Loan Purchase And Sold			$ 5,000,000,000	$ 5,200,000,000
Subsequent Event [Member] | Telephone Consumer Protection Act Litigation [Member]
Loss Contingencies [Line Items]
Damages sought, per violation (at least)	$ 500