Loans And Allowance For Loan Losses (Carrying Amounts At Acquisition Of All Purchased Loans (Impaired And Non-Impaired) Acquired) (Detail) (Parkvale Financial Corporation [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required cash flows at acquisition	$ 1,339,566
Non-accretable difference (expected losses and foregone interest)	(220,611)
Cash flows expected to be collected at acquisition	1,118,955
Accretable yield	(294,183)
Basis in acquired loans at acquisition	824,772
Acquired Impaired Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required cash flows at acquisition	12,224
Non-accretable difference (expected losses and foregone interest)	(6,070)
Cash flows expected to be collected at acquisition	6,154
Accretable yield	(589)
Basis in acquired loans at acquisition	5,565
Acquired Performing Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Contractually required cash flows at acquisition	1,327,342
Non-accretable difference (expected losses and foregone interest)	(214,541)
Cash flows expected to be collected at acquisition	1,112,801
Accretable yield	(293,594)
Basis in acquired loans at acquisition	$ 819,207

Loans And Allowance For Loan Losses (Carrying Amounts At Acquisition Of All Purchased Loans (Impaired And Non-Impaired) Acquired) (Detail) (Parkvale Financial Corporation [Member], USD $)
In Thousands, unless otherwise specified

Dec. 31, 2012

Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]

Contractually required cash flows at acquisition

$ 1,339,566

Non-accretable difference (expected losses and foregone interest)

(220,611)

Cash flows expected to be collected at acquisition

1,118,955

Accretable yield

(294,183)

Basis in acquired loans at acquisition

824,772

Acquired Impaired Loans [Member]

Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]

Contractually required cash flows at acquisition

12,224

Non-accretable difference (expected losses and foregone interest)

(6,070)

Cash flows expected to be collected at acquisition

6,154

Accretable yield

(589)

Basis in acquired loans at acquisition

5,565

Acquired Performing Loans [Member]

Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]

Contractually required cash flows at acquisition

1,327,342

Non-accretable difference (expected losses and foregone interest)

(214,541)

Cash flows expected to be collected at acquisition

1,112,801

Accretable yield

(293,594)

Basis in acquired loans at acquisition

$ 819,207

- Definition

The price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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- Definition

The investor's estimate, at acquisition, of the amount and timing of undiscounted principal, interest, and other cash flows expected to be collected. This would be the investor's best estimate of cash flows, including the effect of prepayments if considered, that is used in determining the acquisition price, and, in a business combination, the investor's estimate of fair value for purposes of acquisition price allocation. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References+ Details

- Definition

The total undiscounted amount of all uncollected contractual principal and contractual interest payments both past due and scheduled for the future, adjusted for the timing of prepayments, if considered, less any reduction by the investor at the acquisition date. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References+ Details