Disclosures About Fair Value of Financial Instruments - Additional Quantitative Information about Assets Measured at Fair Value on Nonrecurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Mortgage servicing rights range weighted average discount rate	9.50%	9.50%
Mortgage servicing rights range weighted average remaining term	10.50%	10.50%
Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Mortgage Servicing Rights	7.80%	7.80%
Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Mortgage Servicing Rights	17.20%	17.20%
Unobservable Input Appraisal Adjustments [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired loans range weighted average		0.00%
Impaired loans range weighted average	10.70%
Unobservable Input Appraisal Adjustments [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired loans range weighted average	25.80%
Unobservable Input Appraisal Adjustments [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired loans range weighted average	0.00%
Unobservable Input Liquidation Expenses [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired loans range weighted average	21.80%	20.50%
Unobservable Input Liquidation Expenses [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired loans range weighted average	13.90%	15.80%
Unobservable Input Liquidation Expenses [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired loans range weighted average	28.50%	23.10%
Valuation Techniques Appraisal of Collateral [Member] | Fair Value Hedging [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impaired Loans	$ 326	$ 372
Valuation Techniques Discounted Cash Flow [Member] | Fair Value Hedging [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Mortgage servicing rights	$ 1	$ 1