Investment Securities Held to Maturity (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	$ 296,522	$ 299,261	$ 273,626
Held-to-Maturity Securities, at Fair Value	302,567	302,305	278,390
Gross Unrealized Gains	6,207	4,786	5,332
Gross Unrealized Losses	162	1,742	568
Held-To-Maturity Securities, Pledged as Collateral	277,636	298,261	272,626
Maturities of Debt Securities at Amortized Cost
Within One Year	33,517
From 1 - 5 Years	147,671
From 5 - 10 Years	112,075
Over 10 Years	3,259
Maturities of Debt Securities, at Fair Value
Within One Year	33,608
From 1 - 5 Years	150,606
From 5 - 10 Years	114,994
Over 10 Years	3,359
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	11,510	108,972	57,528
12 Months or Longer	17,424	5,111	171
Total	28,934	114,083	57,699
Number of Securities in a Continuous Loss Position, in number of securities	63	137	110
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	47	1,683	565
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	115	59	2
Total	162	1,742	567
State and Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	178,699	198,206	194,065
Held-to-Maturity Securities, at Fair Value	184,116	202,390	198,548
Gross Unrealized Gains	5,535	4,762	5,018
Gross Unrealized Losses	118	578	535
Maturities of Debt Securities at Amortized Cost
Within One Year	33,517
From 1 - 5 Years	86,414
From 5 - 10 Years	56,509
Over 10 Years	2,259
Maturities of Debt Securities, at Fair Value
Within One Year	33,608
From 1 - 5 Years	89,028
From 5 - 10 Years	59,121
Over 10 Years	2,359
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	2,289	23,633	27,814
12 Months or Longer	13,058	5,111	171
Total	15,347	28,744	27,985
Number of Securities in a Continuous Loss Position, in number of securities	58	101	97
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	15	519	532
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	103	59	2
Total	118	578	534
Mortgage-Backed Securities - Residential [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	116,823	100,055	78,561
Held-to-Maturity Securities, at Fair Value	117,451	98,915	78,842
Gross Unrealized Gains	672	24	314
Gross Unrealized Losses	44	1,164	33
Maturities of Debt Securities at Amortized Cost
Within One Year	0
From 1 - 5 Years	61,257
From 5 - 10 Years	55,566
Over 10 Years	0
Maturities of Debt Securities, at Fair Value
Within One Year	0
From 1 - 5 Years	61,578
From 5 - 10 Years	55,873
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	9,221	85,339	29,714
12 Months or Longer	4,366	0	0
Total	13,587	85,339	29,714
Number of Securities in a Continuous Loss Position, in number of securities	5	36	13
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	32	1,164	33
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	12	0	0
Total	44	1,164	33
Mortgage-Backed Securities - Residential [Member] | U.S. Government Agency Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	4,500	4,900	5,000
Held-to-Maturity Securities, at Fair Value	4,600	4,700	4,900
Mortgage-Backed Securities - Residential [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	112,300	95,200	73,600
Held-to-Maturity Securities, at Fair Value	112,900	94,200	73,900
Corporate and Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	1,000	1,000	1,000
Held-to-Maturity Securities, at Fair Value	1,000	1,000	1,000
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	0	0	0
Maturities of Debt Securities at Amortized Cost
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	0
Over 10 Years	1,000
Maturities of Debt Securities, at Fair Value
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	0
Over 10 Years	1,000
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	0	0	0
12 Months or Longer	0	0	0
Total	0	0	0
Number of Securities in a Continuous Loss Position, in number of securities	0	0	0
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	0	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0	0
Total	$ 0	$ 0	$ 0