XML 93 R82.htm IDEA: XBRL DOCUMENT v3.5.0.2
Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Summary of Commercial and Standby Letters of Credit (Additional Information) (Detail) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2016
Dec. 31, 2015
Jun. 30, 2015
Venture capital and private equity fund investments      
Commitments and Contingencies Disclosure [Line Items]      
Commitments to invest, period from the inception of the fund 10 years    
Call unrestricted, percentage of committed capital 100.00%    
Venture capital and private equity fund investments | Lower Limit      
Commitments and Contingencies Disclosure [Line Items]      
Expected commitment period to invest in venture capital and private equity funds (in years) 5 years    
Venture capital and private equity fund investments | Upper Limit      
Commitments and Contingencies Disclosure [Line Items]      
Expected commitment period to invest in venture capital and private equity funds (in years) 7 years    
Standby Letter of Credit      
Commitments and Contingencies Disclosure [Line Items]      
Deferred fees   $ 10.0 $ 10.0
Collateral in the form of cash $ 776.0    
Collateral in the form of investment securities $ 0.5