Long-Term Debt - Summary of Long-term Debt (Parenthetical) (Detail)	Dec. 31, 2013
Federal Home Loan Bank advances [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	0.28%
Fixed Rate [Member] \| Medium-term notes [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	2.78%

Weighted average interest rate of long-term debt outstanding.

No definition available.

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant