Fair Value (Quantitative Information About Recurring Level Three Fair Value Measurements ) (Detail) (USD $) In Thousands, unless otherwise specified					9 Months Ended															9 Months Ended																									9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Corporate	Dec. 31, 2012 Corporate	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Non-residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Owner occupied properties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Non owner occupied propertiesproperties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Home Equity Line Of Credit [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Other [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Other real estate owned [Member] Non-residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Commercial [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Residential Real Estate [Member] Home Equity Line Of Credit [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Residential Real Estate [Member] Other [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Non Residential Real Estate [Member] Owner occupied properties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Non Residential Real Estate [Member] Non owner occupied propertiesproperties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Cost Sales Income Approach Valuation Technique [Member] Construction [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Corporate	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) [Member] Corporate	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Non-residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Owner occupied properties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Non owner occupied propertiesproperties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Home Equity Line Of Credit [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Other [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Commercial [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Maximum [Member] Cost Sales Income Approach Valuation Technique [Member] Construction [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Non-residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Owner occupied properties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Non owner occupied propertiesproperties	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Residential [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Home Equity Line Of Credit [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Other [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Commercial [Member]	Sep. 30, 2013 Significant Unobservable Inputs (Level 3) [Member] Minimum [Member] Cost Sales Income Approach Valuation Technique [Member] Construction [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Residential [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Other real estate owned [Member] Non-residential [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Commercial [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Residential Real Estate [Member] Home Equity Line Of Credit [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Residential Real Estate [Member] Other [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Non Residential Real Estate [Member] Owner occupied properties	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Non Residential Real Estate [Member] Non owner occupied propertiesproperties	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Construction [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Corporate Discounted Cash Flows Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Investment securities available-for-sale	$ 310,558	$ 314,444	$ 995	$ 1,060														$ 995	$ 1,060																										$ 995
Probability of default																																													0.00%
Impaired loans	$ 1,192,268	$ 1,182,273																																		$ 17,960	$ 195	$ 3,268	$ 3,393	$ 218	$ 4,064	$ 5,157	$ 869	$ 796
Unobservable Input, discounts ranging					0.00%	10.00%	4.00%	0.00%	14.00%	9.00%		45.00%					21.00%			0.00%	90.00%	100.00%	0.00%	95.00%	100.00%	95.00%	100.00%	0.00%	0.00%	80.00%	0.00%	85.00%	0.00%	0.00%	0.00%
Valuation Techniques								Cost, sales, income approach			Cost, sales, income approach	Cost, sales, income approach	Cost, sales, income approach	Cost, sales, income approach	Cost, sales, income approach	Cost, sales, income approach	Cost, sales, income approach