Loans and Leases - Composition of Lakeland`s Loan and Lease Portfolio (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 2,428,750	$ 2,147,207
Plus: deferred fees	(1,066)	(364)
Loans, net of deferred fees	2,427,684	2,146,843
Commercial, Secured by Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,348,314	1,125,137
Commercial, Industrial and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	214,877	216,129
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	37,845	26,781
Real Estate - Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	437,788	423,262
Real Estate - Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	50,121	46,272
Home Equity and Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 339,805	$ 309,626