Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 5,166	$ 4,297
Net change in fair value of interest rate swap agreements designated as cash flow hedges:
Unrealized gain (loss) on interest rate swaps, net of tax of $21 and ($6), respectively	(39)	12
Reclassification adjustment for losses recognized in earnings, net of tax of ($34) and ($34), respectively	63	63
Net change in fair value of interest rate swap agreements designated as cash flow hedges	24	75
Unrealized gains (losses) on other-than-temporarily impaired securities available for sale:
Unrealized gains (losses) arising during the period, net of tax of ($48) and $15, respectively	89	(27)
Unrealized gains (losses) on other securities available for sale:
Unrealized gains (losses) arising during the period, net of tax of $2,306 and $865, respectively	4,283	(1,606)
Reclassification adjustment for realized gains included in net income, net of tax of $23 and $27, respectively	(43)	(49)
Unrealized losses on other securities available for sale net of reclassification adjustment for realized gains included in net income	4,240	(1,655)
Other comprehensive income (loss)	4,353	(1,607)
COMPREHENSIVE INCOME	$ 9,519	$ 2,690