Quantitative inputs level 3 (Detail) (USD $) In Thousands, unless otherwise specified											9 Months Ended											9 Months Ended			9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2014 Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2013 Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2014 Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Contingent Liability [Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Contingent Liability [Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Recurring [Member] Risk Premium [Member]	Sep. 30, 2014 Servicing Asset At Fair Value Amount [Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Loan Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2014 Real Estate Acquired in Satisfaction of Debt [Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2014 Other Foreclosed Acquired In Satisfaction Of Debt [Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Nonrecurring [Member]		Sep. 30, 2014 Collateralized Mortgage Obligations Member Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Collateralized Mortgage Obligations Member Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Collateralized Mortgage Obligations Member Trading Account Assets[Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Other Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Other Securities [Member] Fair Value, Measurements, Recurring [Member]	Sep. 30, 2014 Other Securities [Member] Trading Account Assets[Member] Fair Value Inputs Level 3 Internal Valuation Technique [Member] Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure [Abstract]
Trading Securities	$ 145,343	$ 339,743			$ 145,343	$ 339,660														$ 1,749	$ 1,849	$ 1,449	$ 17,398	$ 17,474	$ 816
Servicing Asset At Fair Value Amount	152,282	161,099	161,445	154,430	152,282	161,099							152,282
Loans Receivable, Fair Value Disclosure							53,796	[1]	31,628	[1]				53,136	[2]
Real Estate Acquired Through Foreclosure							79,236	[3]	77,208	[3]						79,236	[4]
Other Foreclosed Assets							1,612	[3]	407	[3]								1,465	[5]
Liabilities, Fair Value Disclosure [Abstract]
Business Combination Contingent Consideration Liability					$ (126,473)	$ (128,299)					$ (126,473)
Fair Value Inputs [Abstract]
Fair Value Measurements, Valuation Techniques											Discounted cash flow model		Discounted cash flow model	External appraisal		External appraisal		External appraisal				Discounted cash flow model			Discounted cash flow model
Unobservable Inputs											Credit loss rate on covered loans of discount rate Risk premium component		Prepayment speed Weighted average life Discount rate	Haircut applied on external appraisals		Haircut applied on external appraisals		external appraisals Haircut applied on				Weighted average life Yield Constant prepayment rate			Weighted average life Yield Constant prepayment rate
Fair Value Inputs Quantitative Information [Abstract]
Fair Value Inputs Weighted Average Life And Range													12.8 years (4.3- 18.0 years)									2.2 years (0.6 - 5.0 years)			5.5
Fair Value Inputs Prepayment Rate																									10.80%
Fair Value Inputs Prepayment Weighted Average And Range													7.8% (5.6% - 23.1%)									23.9% (19.5% - 27.1%)
Fair Value Inputs Yield																						3.9% (1.4% - 4.7%)			12.0
Fair Value Inputs Credit Loss Rate											8.1% (0.0% - 100.0%)
Fair Value Inputs Discount Rate Weighted Average And Range												5.0	11.3% (9.5% - 15.0%)
Fair Value Inputs Haircut External Appraisal														16.5% (15.0% - 25.0%)		15.5% (5.0% -35.0%)		3.0% (1.0% -6.0%)

[1] Relates mostly to certain impaired collateral dependent loans. The impairment was measured based on the fair value of the collateral, which is derived from appraisals that take into consideration prices in observed transactions involving similar assets in similar locations, in accordance with the provisions of ASC Section 310-10-35. Costs to sell are excluded from the reported fair value amount.

[2] Loans held-in-portfolio in which haircuts were not applied to external appraisals were excluded from this table.

[3] Represents the fair value of foreclosed real estate and other collateral owned that were written down to their fair value. Costs to sell are excluded from the reported fair value amount.

[4] Other real estate owned in which haircuts were not applied to external appraisals were excluded from this table.

[5] Other foreclosed assets in which haircuts were not applied to external appraisals were excluded from this table.