Investment Securities Held to Maturity (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	$ 297,437	$ 299,261	$ 248,914
Held-to-Maturity Securities, at Fair Value	304,259	302,305	252,691
Gross Unrealized Gains	7,006	4,786	4,841
Gross Unrealized Losses	184	1,742	1,064
Held-To-Maturity Securities, Pledged as Collateral	296,437	298,261	247,914
Maturities of Debt Securities at Amortized Cost
Within One Year	30,255
From 1 - 5 Years	118,893
From 5 - 10 Years	144,834
Over 10 Years	3,455
Maturities of Debt Securities, at Fair Value
Within One Year	30,369
From 1 - 5 Years	121,837
From 5 - 10 Years	148,499
Over 10 Years	3,554
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	12,258	108,972	82,411
12 Months or Longer	15,033	5,111	13,204
Total	27,291	114,083	95,615
Number of Securities in a Continuous Loss Position, in number of securities	67	137	199
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	56	1,683	915
12 Months or Longer	128	59	149
Total	184	1,742	1,064
State and Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	174,888	198,206	200,182
Held-to-Maturity Securities, at Fair Value	180,211	202,390	204,153
Gross Unrealized Gains	5,473	4,762	4,833
Gross Unrealized Losses	150	578	862
Maturities of Debt Securities at Amortized Cost
Within One Year	30,255
From 1 - 5 Years	81,521
From 5 - 10 Years	60,657
Over 10 Years	2,455
Maturities of Debt Securities, at Fair Value
Within One Year	30,369
From 1 - 5 Years	84,085
From 5 - 10 Years	63,203
Over 10 Years	2,554
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	2,697	23,633	39,598
12 Months or Longer	13,839	5,111	13,204
Total	16,536	28,744	52,802
Number of Securities in a Continuous Loss Position, in number of securities	63	101	172
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	29	519	712
12 Months or Longer	121	59	149
Total	150	578	861
Mortgage-Backed Securities - Residential [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	121,549	100,055	47,732
Held-to-Maturity Securities, at Fair Value	123,048	98,915	47,538
Gross Unrealized Gains	1,533	24	8
Gross Unrealized Losses	34	1,164	202
Maturities of Debt Securities at Amortized Cost
Within One Year	0
From 1 - 5 Years	37,372
From 5 - 10 Years	84,177
Over 10 Years	0
Maturities of Debt Securities, at Fair Value
Within One Year	0
From 1 - 5 Years	37,752
From 5 - 10 Years	85,296
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	9,561	85,339	42,813
12 Months or Longer	1,194	0	0
Total	10,755	85,339	42,813
Number of Securities in a Continuous Loss Position, in number of securities	4	36	27
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	27	1,164	203
12 Months or Longer	7	0	0
Total	34	1,164	203
Mortgage-Backed Securities - Residential [Member] | U.S. Government Agency Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	4,600	4,900
Held-to-Maturity Securities, at Fair Value	4,700	4,700
Mortgage-Backed Securities - Residential [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity	116,900	95,200	47,700
Held-to-Maturity Securities, at Fair Value	118,300	94,200	47,500
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
12 Months or Longer	0	0	0
Total	$ 0	$ 0	$ 0