Loans and Loans Held for Sale - Restructured Loans for Periods Presented (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended					12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014 Accruing TDRs [Member]	Dec. 31, 2013 Accruing TDRs [Member]	Jun. 30, 2014 Accruing TDRs [Member] Commercial Real Estate [Member]	Dec. 31, 2013 Accruing TDRs [Member] Commercial Real Estate [Member]	Jun. 30, 2014 Accruing TDRs [Member] Commercial and Industrial [Member]	Dec. 31, 2013 Accruing TDRs [Member] Commercial and Industrial [Member]	Jun. 30, 2014 Accruing TDRs [Member] Commercial Construction [Member]	Dec. 31, 2013 Accruing TDRs [Member] Commercial Construction [Member]	Jun. 30, 2014 Accruing TDRs [Member] Residential Mortgage [Member]	Dec. 31, 2013 Accruing TDRs [Member] Residential Mortgage [Member]	Jun. 30, 2014 Accruing TDRs [Member] Home Equity [Member]	Dec. 31, 2013 Accruing TDRs [Member] Home Equity [Member]	Jun. 30, 2014 Accruing TDRs [Member] Installment and Other Consumer [Member]	Dec. 31, 2013 Accruing TDRs [Member] Installment and Other Consumer [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member] Commercial Real Estate [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member] Commercial Real Estate [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member] Commercial and Industrial [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member] Commercial and Industrial [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member] Commercial Construction [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member] Commercial Construction [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member] Residential Mortgage [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member] Residential Mortgage [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member] Home Equity [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member] Home Equity [Member]	Jun. 30, 2014 Nonaccruing TDRs [Member] Installment and Other Consumer [Member]	Dec. 31, 2013 Nonaccruing TDRs [Member] Installment and Other Consumer [Member]	Jun. 30, 2014 Total TDRs [Member]	Dec. 31, 2013 Total TDRs [Member]	Jun. 30, 2014 Total TDRs [Member] Commercial Real Estate [Member]	Dec. 31, 2013 Total TDRs [Member] Commercial Real Estate [Member]	Jun. 30, 2014 Total TDRs [Member] Commercial and Industrial [Member]	Dec. 31, 2013 Total TDRs [Member] Commercial and Industrial [Member]	Jun. 30, 2014 Total TDRs [Member] Commercial Construction [Member]	Dec. 31, 2013 Total TDRs [Member] Commercial Construction [Member]	Jun. 30, 2014 Total TDRs [Member] Residential Mortgage [Member]	Dec. 31, 2013 Total TDRs [Member] Residential Mortgage [Member]	Jun. 30, 2014 Total TDRs [Member] Home Equity [Member]	Dec. 31, 2013 Total TDRs [Member] Home Equity [Member]	Jun. 30, 2014 Total TDRs [Member] Installment and Other Consumer [Member]	Dec. 31, 2013 Total TDRs [Member] Installment and Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	$ 229	[1]	$ 5,694	[1]	$ 2,019	[1]	$ 8,278	[1]	$ 37,120	$ 39,229	$ 16,934	$ 19,711	$ 7,390	$ 7,521	$ 6,310	$ 5,338	$ 2,647	$ 2,581	$ 3,712	$ 3,924	$ 127	$ 154	$ 5,241	$ 10,067	$ 1,431	$ 3,898	$ 1,170	$ 1,884	$ 1,869	$ 2,708	$ 645	$ 1,356	$ 125	$ 218	$ 1	$ 3	$ 42,361	$ 49,296	$ 18,365	$ 23,609	$ 8,560	$ 9,405	$ 8,179	$ 8,046	$ 3,292	$ 3,937	$ 3,837	$ 4,142	$ 128	$ 157

[1] Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.