Derivative Instruments and Hedging Activities - Gains (Losses) Related to Interest Rate Derivatives Designated as Hedges of Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Amounts Related To Interest Rate Derivatives Designated As Hedges Of Fair Value [Line Items]
Interest income - interest and fees on loans	$ 133,966	$ 143,812	$ 266,965	$ 292,272
Interest expense - interest on time deposits	42,483	44,787	85,480	91,464
Interest rate caps and swaps, Assets [Member] | Derivatives not designated as hedging instrument [Member]
Amounts Related To Interest Rate Derivatives Designated As Hedges Of Fair Value [Line Items]
Interest income - interest and fees on loans	425	(251)	522	(121)
Interest rate caps and swaps, Assets [Member] | Derivatives designated as hedging instruments [Member]
Amounts Related To Interest Rate Derivatives Designated As Hedges Of Fair Value [Line Items]
Interest income - interest and fees on loans	(425)	251	(522)	121
Liability [Member] | Derivatives not designated as hedging instrument [Member]
Amounts Related To Interest Rate Derivatives Designated As Hedges Of Fair Value [Line Items]
Interest expense - interest on time deposits	(134)	(67)	(274)	(27)
Liability [Member] | Derivatives designated as hedging instruments [Member]
Amounts Related To Interest Rate Derivatives Designated As Hedges Of Fair Value [Line Items]
Interest expense - interest on time deposits	$ 136	$ 70	$ 279	$ 38