Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	$ 251,092	$ 250,371
Balance at end of period	239,545	253,625
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications before tax	6,057	5,561
Income tax expense	1,957	1,780
Reclassifications, net of tax	4,100	3,781
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(6,036)	(5,636)
Other comprehensive income before reclassifications	1,349	1,483
Amounts reclassified from AOCL	(112)	(49)
Net current period other comprehensive income	1,237	1,434
Balance at end of period	(4,799)	(4,202)
Unrealized Gains (Losses) on Available For Sale Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(238)	162
Other comprehensive income before reclassifications	1,349	1,483
Amounts reclassified from AOCL	(112)	(49)
Net current period other comprehensive income	1,237	1,434
Balance at end of period	999	1,596
Unrealized Gains (Losses) on Available For Sale Securities [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net gains on securities	174	75
Net impairment loss recognized in earnings	0	0
Total reclassifications before tax	174	75
Income tax expense	62	26
Reclassifications, net of tax	112	49
Disproportionate Tax Effects from Securities Available for Sale [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(5,798)	(5,798)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from AOCL	0	0
Net current period other comprehensive income	0	0
Balance at end of period	$ (5,798)	$ (5,798)