Borrowings - Summary of Bancorps Short Term Borrowings (Detail) (USD $) In Thousands, unless otherwise specified
|
12 Months Ended |
Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2012
|
FHLB Advances |
|
|
|
Short-term Debt [Line Items] |
|
|
|
Maximum outstanding at any month end |
$ 1,383,000us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
$ 769,750us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
$ 411,000us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
Average balance during the year |
898,396us-gaap_ShorttermDebtAverageOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
120,309us-gaap_ShorttermDebtAverageOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
74,336us-gaap_ShorttermDebtAverageOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
Weighted-average interest rate during the year |
0.46%us-gaap_ShortTermDebtWeightedAverageInterestRate / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
0.55%us-gaap_ShortTermDebtWeightedAverageInterestRate / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
0.38%us-gaap_ShortTermDebtWeightedAverageInterestRate / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalHomeLoanBankAdvancesMember |
Federal Funds Purchased |
|
|
|
Short-term Debt [Line Items] |
|
|
|
Maximum outstanding at any month end |
35,000us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
125,000us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
55,000us-gaap_ShorttermDebtMaximumMonthendOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
Average balance during the year |
$ 13,312us-gaap_ShorttermDebtAverageOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
$ 32,351us-gaap_ShorttermDebtAverageOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
$ 4,336us-gaap_ShorttermDebtAverageOutstandingAmount / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
Weighted-average interest rate during the year |
0.31%us-gaap_ShortTermDebtWeightedAverageInterestRate / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
0.31%us-gaap_ShortTermDebtWeightedAverageInterestRate / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |
0.24%us-gaap_ShortTermDebtWeightedAverageInterestRate / us-gaap_ShortTermDebtTypeAxis = us-gaap_FederalFundsPurchasedMember |