Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Detail) - Allowance for Credit Losses (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for loan and covered loan losses	$ 16,257	$ 158,052	$ 80,582
Commercial Industrial And Agricultural
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	36,761	46,017	49,545
Charge-offs	(12,094)	(64,668)	(32,750)
Recoveries	3,797	3,393	3,493
Net charge-offs	(8,297)	(61,275)	(29,257)
Provision for loan and covered loan losses	1,917	52,019	25,729
Balance at the end of the year	30,381	36,761	46,017
Office Retail And Industrial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	11,432	16,012	20,758
Charge-offs	(4,744)	(34,968)	(8,193)
Recoveries	228	577	79
Net charge-offs	(4,516)	(34,391)	(8,114)
Provision for loan and covered loan losses	3,489	29,811	3,368
Balance at the end of the year	10,405	11,432	16,012
Multi Family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	3,575	5,067	3,996
Charge-offs	(1,029)	(3,361)	(14,584)
Recoveries	584	275	410
Net charge-offs	(445)	(3,086)	(14,174)
Provision for loan and covered loan losses	(1,113)	1,594	15,245
Balance at the end of the year	2,017	3,575	5,067
Construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	9,223	17,795	32,140
Charge-offs	(1,916)	(27,811)	(20,211)
Recoveries	1,032	451	2,964
Net charge-offs	(884)	(27,360)	(17,247)
Provision for loan and covered loan losses	(2,023)	18,788	2,902
Balance at the end of the year	6,316	9,223	17,795
Other Commerical Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	13,531	19,451	23,655
Charge-offs	(4,784)	(36,474)	(15,396)
Recoveries	1,646	125	508
Net charge-offs	(3,138)	(36,349)	(14,888)
Provision for loan and covered loan losses	424	30,429	10,684
Balance at the end of the year	10,817	13,531	19,451
Consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	12,862	14,131	12,478
Charge-offs	(9,414)	(10,910)	(10,531)
Recoveries	1,071	784	430
Net charge-offs	(8,343)	(10,126)	(10,101)
Provision for loan and covered loan losses	8,491	8,857	11,754
Balance at the end of the year	13,010	12,862	14,131
Covered Loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	12,062	989	0
Charge-offs	(4,599)	(4,615)	(9,911)
Recoveries	24	0	0
Net charge-offs	(4,575)	(4,615)	(9,911)
Provision for loan and covered loan losses	5,072	15,688	10,900
Balance at the end of the year	12,559	12,062	989
Reservefor Unfunded Commitments
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	3,366	2,500	2,500
Charge-offs	0	0	0
Recoveries	0	0	0
Net charge-offs	0	0	0
Provision for loan and covered loan losses	(1,750)	866	0
Balance at the end of the year	1,616	3,366	2,500
Total Allowance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at the beginning of the year	102,812	121,962	145,072
Charge-offs	(38,580)	(182,807)	(111,576)
Recoveries	8,382	5,605	7,884
Net charge-offs	(30,198)	(177,202)	(103,692)
Provision for loan and covered loan losses	14,507	158,052	80,582
Balance at the end of the year	$ 87,121	$ 102,812	$ 121,962