Restructuring plan (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment, Continuing Operations [Member]
Restructuring Cost And Reserve [Line Items]
Personnel costs	$ 99,100	$ 106,359	$ 203,401	$ 213,940
Net occupancy expenses	20,267	21,059	41,627	41,551
Equipment Expense	12,044	11,485	23,456	23,105
Professional fees	67,024	67,015	134,023	134,752
Other operating expenses	20,509	22,766	42,858	43,684
Restructuring Charges Member
Restructuring Cost And Reserve [Line Items]
Personnel costs	3,630
Net occupancy expenses	271
Equipment Expense	190
Professional fees	448
Other operating expenses	35
Restructuring Charges Member | Segment, Continuing Operations [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 4,574	$ 0	$ 4,574	$ 0