Borrowings - Summary of Information Pertaining to Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Long Term And Short Term Debt [Line Items]
Short-term borrowings	$ 138,434	$ 173,847
Long-term borrowings	66,845	67,429
Total Borrowings	205,279	241,276
Short-term borrowings, Weighted Average Rate	0.22%	0.24%
Long-term borrowings, Weighted Average Rate	2.79%	2.80%
Total Borrowings, Weighted Average Rate	1.06%	0.96%
Securities Sold under Repurchase Agreements [Member]
Long Term And Short Term Debt [Line Items]
Short-term borrowings	38,434	33,847
Short-term borrowings, Weighted Average Rate	0.01%	0.01%
Short-Term Borrowings [Member]
Long Term And Short Term Debt [Line Items]
Short-term borrowings	100,000	140,000
Short-term borrowings, Weighted Average Rate	0.31%	0.30%
Junior Subordinated Debt Securities [Member]
Long Term And Short Term Debt [Line Items]
Long-term borrowings	21,226	21,810
Long-term borrowings, Weighted Average Rate	2.99%	3.01%
Other Long-Term Borrowings [Member]
Long Term And Short Term Debt [Line Items]
Long-term borrowings	$ 45,619	$ 45,619
Long-term borrowings, Weighted Average Rate	2.69%	2.70%