Incentive Plans - Summary of Impact of Share-Based Incentive Plans on Compensation and Benefits Expense (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended	15 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost saving initiatives and staff reductions, charges	$ 64,703	$ 167,279
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost saving initiatives and staff reductions, charges	9,099		26,158
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost saving initiatives and staff reductions, charges	$ 247		$ 713