Investment Securities Available for Sale (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	$ 498,467	$ 469,384	$ 419,805
Available-for-Sale	501,574	478,698	431,010
Gross Unrealized Gains	5,744	9,843	11,609
Gross Unrealized Losses	2,637	529	404
Available-For-Sale Securities, Pledged as Collateral	270,243	260,292	184,631
Maturities of Debt Securities, at Amortized Cost
Within One Year	66,690
From 1 - 5 Years	415,956
From 5 - 10 Years	13,021
Over 10 Years	1,680
Maturities of Debt Securities at Fair Value
Within One Year	67,470
From 1 - 5 Years	417,812
From 5 - 10 Years	13,669
Over 10 Years	1,480
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	253,151	137,839	32,914
12 Months or Longer	5,028	7,117	39
Total	258,179	144,956	32,953
Number of Securities in a Continuous Loss Position, in number of securities	419	238	40
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	2,418	492	398
12 Months or Longer	219	37	6
Total	2,637	529	404
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	34,100		42,500
Available-for-Sale	35,100		44,000
US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	163,700		271,900
Available-for-Sale	168,100		281,100
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	151,200		48,300
Available-for-Sale	150,000		48,700
U.S. Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	151,199	122,297	48,300
Available-for-Sale	150,046	122,457	48,655
Gross Unrealized Gains	0	204	355
Gross Unrealized Losses	1,153	44	0
Maturities of Debt Securities, at Amortized Cost
Within One Year	0
From 1 - 5 Years	151,199
From 5 - 10 Years	0
Over 10 Years	0
Maturities of Debt Securities at Fair Value
Within One Year	0
From 1 - 5 Years	150,046
From 5 - 10 Years	0
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	150,048	72,531	0
12 Months or Longer	0	0	0
Total	150,048	72,531	0
Number of Securities in a Continuous Loss Position, in number of securities	47	22	0
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	1,153	44	0
12 Months or Longer	0	0	0
Total	1,153	44	0
State and Municipal Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	131,154	84,798	54,746
Available-for-Sale	130,444	84,838	55,013
Gross Unrealized Gains	135	206	284
Gross Unrealized Losses	845	166	17
Maturities of Debt Securities, at Amortized Cost
Within One Year	47,464
From 1 - 5 Years	80,191
From 5 - 10 Years	2,819
Over 10 Years	680
Maturities of Debt Securities at Fair Value
Within One Year	47,501
From 1 - 5 Years	79,434
From 5 - 10 Years	2,829
Over 10 Years	680
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	80,443	46,627	8,637
12 Months or Longer	4,228	2,149	0
Total	84,671	48,776	8,637
Number of Securities in a Continuous Loss Position, in number of securities	347	198	29
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	826	160	17
12 Months or Longer	19	6	0
Total	845	166	17
Mortgage-Backed Securities - Residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	197,775	252,480	314,394
Available-for-Sale	203,230	261,804	325,076
Gross Unrealized Gains	5,586	9,405	10,863
Gross Unrealized Losses	131	81	181
Maturities of Debt Securities, at Amortized Cost
Within One Year	19,226
From 1 - 5 Years	168,347
From 5 - 10 Years	10,202
Over 10 Years	0
Maturities of Debt Securities at Fair Value
Within One Year	19,969
From 1 - 5 Years	172,421
From 5 - 10 Years	10,840
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	6,750	10,230	23,477
12 Months or Longer	0	4,968	0
Total	6,750	15,198	23,477
Number of Securities in a Continuous Loss Position, in number of securities	3	7	9
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	131	50	181
12 Months or Longer	0	31	0
Total	131	81	181
Corporate and Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	17,219	8,689	1,001
Available-for-Sale	16,711	8,451	801
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	508	238	200
Maturities of Debt Securities, at Amortized Cost
Within One Year	0
From 1 - 5 Years	16,219
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	15,911
From 5 - 10 Years	0
Over 10 Years	800
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	15,910	8,451	800
12 Months or Longer	800	0	0
Total	16,710	8,451	800
Number of Securities in a Continuous Loss Position, in number of securities	22	11	1
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	308	238	200
12 Months or Longer	200	0	0
Total	508	238	200
Mutual Funds and Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	1,120	1,120	1,364
Available-for-Sale	1,143	1,148	1,465
Gross Unrealized Gains	23	28	107
Gross Unrealized Losses	0	0	6
Securities in a Continuous Loss Position, at Fair Value
Less than 12 Months	0	0	0
12 Months or Longer	0	0	39
Total	0	0	39
Number of Securities in a Continuous Loss Position, in number of securities	0	0	1
Unrealized Losses on Securities in a Continuous Loss Position
Less than 12 Months	0	0	0
12 Months or Longer	0	0	6
Total	$ 0	$ 0	$ 6