Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended							12 Months Ended		12 Months Ended							12 Months Ended						12 Months Ended			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Interest Rate Swaps [Member]	Dec. 31, 2012 Interest Rate Swaps [Member]	Dec. 31, 2011 Interest Rate Swaps [Member]	Dec. 31, 2013 Interest Rate Swaps [Member] Cash Flow Hedge [Member]	Dec. 31, 2013 Subordinated Notes Due on September 27, 2023 [Member]	Sep. 30, 2013 Forward-Settle Interest Rate Swap [Member] Cash Flow Hedge [Member]	Dec. 31, 2013 Interest Rate Caps [Member]	Dec. 31, 2012 Interest Rate Caps [Member]	Dec. 31, 2011 Interest Rate Caps [Member]	Dec. 31, 2013 Certain Counterparties [Member]	Dec. 31, 2013 Customer Repurchase Agreements and Money Market Deposit Accounts [Member] Interest Rate Swaps Due July Twelve Two Thousand Twelve [Member] Cash Flow Hedge [Member]	Dec. 31, 2013 Customer Repurchase Agreements and Money Market Deposit Accounts [Member] Interest Rate Swaps Due July Fifteen Two Thousand Fifteen [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Interest Rate Swaps [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Interest Rate Swaps [Member] Minimum [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Interest Rate Swaps [Member] Maximum [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member] Minimum [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member] Maximum [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member] Interest Rate Swaps [Member] Fair Value Hedge [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member] Interest Rate Swaps [Member] Fixed-Rate at Approximately 4.73% [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member] Interest Rate Swaps [Member] Fixed-Rate at Approximately 5.11% [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Consumer and Commercial Money Market Deposit Accounts [Member] Interest Rate Swaps Due September Twenty Seven Two Thousand Twenty Three [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Customer Repurchase Agreements and Money Market Deposit Accounts [Member] Interest Rate Swaps [Member] Fixed-Rate at Approximately 4.73% [Member]	Dec. 31, 2013 Derivatives Designated as Hedging Instruments [Member] Customer Repurchase Agreements and Money Market Deposit Accounts [Member] Interest Rate Swaps [Member] Fixed-Rate at Approximately 4.73% [Member] Fair Value Hedge [Member]	Dec. 31, 2013 Derivatives Not Designated as Hedging Instrument [Member] Swap
Commitments And Contingencies [Line Items]
Lease expiration date		Through 2058
Net rental expense		$ 19,900,000	$ 23,800,000	$ 21,200,000
Net of rental income		3,300,000	2,500,000	1,800,000
Operating lease termination period	20 years
Gain recognized on lease termination	11,300,000
Notional amount of interest rate derivatives	46,800,000	46,800,000						300,000,000		65,000,000					100,000,000								8,600,000					51,000,000
Aggregate notional amount of interest rate derivatives																100,000,000	482,000,000							200,000,000		125,000,000
Maturity date, derivative instrument		Jul. 15, 2015																Nov. 01, 2018	Nov. 01, 2020	Sep. 27, 2023				Oct. 01, 2016	Jul. 01, 2017		Mar. 01, 2014
Fixed interest rate																		2.51%	2.97%					4.73%	5.11%
Interest rate swap, starting date																								July 2012
Strike rates																				7.44%	6.00%	6.25%
Interest rate swap, starting date																		November 2015	April 2016
Debt instrument, interest rate									5.125%
Debt instrument, issuance date									Sep. 01, 2013
Total interest rate swaps aggregate notional amount																													259,800,000
Number of interest rate swaps																													51
Gain (loss) on cash flow hedge ineffectiveness											0	73,000	(23,000)
Accumulated net after-tax losses related to effective cash flow hedges					6,300,000	12,700,000
Estimated amount of interest rate derivatives to be reclassified to interest expense					8,400,000
Recognized a net reduction to interest expense					584,000	561,000	472,000
Aggregate fair value of net liability position	9,400,000	9,400,000
Collateral posted	$ 23,500,000	$ 23,500,000												$ 800,000