Securities (Details 4) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014 security	Dec. 31, 2013 security
Held-to-maturity Securities [Abstract]
Number of positions (securities)	63	141
Fair Value, Less than 12 Months	$ 7,588	$ 165,250
Unrealized Losses, Less than 12 months	(34)	(10,404)
Fair Value, 12 Months or More	133,948	10,023
Unrealized Losses, 12 Months or More	(4,673)	(1,006)
Fair Value, Total	141,536	175,273
Unrealized Losses, Total	(4,707)	(11,410)
Available-for-sale Securities [Abstract]
Number of positions (securities)	67	68
Fair Value, Less than 12 Months	102,772	230,823
Unrealized Losses, Less than 12 months	(624)	(7,921)
Fair Value, 12 Months or More	170,121	48,342
Unrealized Losses, 12 months or More	(12,945)	(12,120)
Fair Value, Total	272,893	279,165
Unrealized Losses, Total	(13,569)	(20,041)
Trust preferred securities
Available-for-sale Securities [Abstract]
Number of positions (securities)	2	3
Fair Value, Less than 12 Months	0	0
Unrealized Losses, Less than 12 months	0	0
Fair Value, 12 Months or More	18,315	16,456
Unrealized Losses, 12 months or More	(7,307)	(9,933)
Fair Value, Total	18,315	16,456
Unrealized Losses, Total	(7,307)	(9,933)
Other debt securities
Available-for-sale Securities [Abstract]
Number of positions (securities)	3	4
Fair Value, Less than 12 Months	0	7,100
Unrealized Losses, Less than 12 months	0	(217)
Fair Value, 12 Months or More	4,419	1,897
Unrealized Losses, 12 months or More	(106)	(13)
Fair Value, Total	4,419	8,997
Unrealized Losses, Total	(106)	(230)
Other equity securities
Available-for-sale Securities [Abstract]
Number of positions (securities)		0
Fair Value, Less than 12 Months		0
Unrealized Losses, Less than 12 months		0
Fair Value, 12 Months or More		0
Unrealized Losses, 12 months or More		0
Fair Value, Total		0
Unrealized Losses, Total		0
Obligations of other U.S. Government agencies and corporations
Held-to-maturity Securities [Abstract]
Number of positions (securities)	28	28
Fair Value, Less than 12 Months	1,486	105,747
Unrealized Losses, Less than 12 months	(5)	(7,826)
Fair Value, 12 Months or More	118,251	9,090
Unrealized Losses, 12 Months or More	(4,331)	(901)
Fair Value, Total	119,737	114,837
Unrealized Losses, Total	(4,336)	(8,727)
Available-for-sale Securities [Abstract]
Number of positions (securities)	1	1
Fair Value, Less than 12 Months	0	3,799
Unrealized Losses, Less than 12 months	0	(201)
Fair Value, 12 Months or More	3,837	0
Unrealized Losses, 12 months or More	(163)	0
Fair Value, Total	3,837	3,799
Unrealized Losses, Total	(163)	(201)
Obligations of states and political subdivisions
Held-to-maturity Securities [Abstract]
Number of positions (securities)	35	113
Fair Value, Less than 12 Months	6,102	59,503
Unrealized Losses, Less than 12 months	(29)	(2,578)
Fair Value, 12 Months or More	15,697	933
Unrealized Losses, 12 Months or More	(342)	(105)
Fair Value, Total	21,799	60,436
Unrealized Losses, Total	(371)	(2,683)
Government agency mortgage backed securities | Residential mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	33	35
Fair Value, Less than 12 Months	67,667	134,858
Unrealized Losses, Less than 12 months	(195)	(3,451)
Fair Value, 12 Months or More	65,621	13,239
Unrealized Losses, 12 months or More	(1,847)	(963)
Fair Value, Total	133,288	148,097
Unrealized Losses, Total	(2,042)	(4,414)
Government agency mortgage backed securities | Commercial mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	4	4
Fair Value, Less than 12 Months	5,220	16,570
Unrealized Losses, Less than 12 months	(52)	(584)
Fair Value, 12 Months or More	10,569	0
Unrealized Losses, 12 months or More	(256)	0
Fair Value, Total	15,789	16,570
Unrealized Losses, Total	(308)	(584)
Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	24	21
Fair Value, Less than 12 Months	29,885	68,496
Unrealized Losses, Less than 12 months	(377)	(3,468)
Fair Value, 12 Months or More	67,360	16,750
Unrealized Losses, 12 months or More	(3,266)	(1,211)
Fair Value, Total	97,245	85,246
Unrealized Losses, Total	(3,643)	(4,679)
Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	0	0
Fair Value, Less than 12 Months	0	0
Unrealized Losses, Less than 12 months	0	0
Fair Value, 12 Months or More	0	0
Unrealized Losses, 12 months or More	0	0
Fair Value, Total	0	0
Unrealized Losses, Total	$ 0	$ 0
Less than 12 Months
Held-to-maturity Securities [Abstract]
Number of positions (securities)	8	137
Available-for-sale Securities [Abstract]
Number of positions (securities)	22	57
Less than 12 Months | Trust preferred securities
Available-for-sale Securities [Abstract]
Number of positions (securities)	0	0
Less than 12 Months | Other debt securities
Available-for-sale Securities [Abstract]
Number of positions (securities)	0	3
Less than 12 Months | Other equity securities
Available-for-sale Securities [Abstract]
Number of positions (securities)		0
Less than 12 Months | Obligations of other U.S. Government agencies and corporations
Held-to-maturity Securities [Abstract]
Number of positions (securities)	1	26
Available-for-sale Securities [Abstract]
Number of positions (securities)	0	1
Less than 12 Months | Obligations of states and political subdivisions
Held-to-maturity Securities [Abstract]
Number of positions (securities)	7	111
Less than 12 Months | Government agency mortgage backed securities | Residential mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	15	32
Less than 12 Months | Government agency mortgage backed securities | Commercial mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	1	4
Less than 12 Months | Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	6	17
Less than 12 Months | Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	0	0
12 Months or More
Held-to-maturity Securities [Abstract]
Number of positions (securities)	55	4
Available-for-sale Securities [Abstract]
Number of positions (securities)	45	11
12 Months or More | Trust preferred securities
Available-for-sale Securities [Abstract]
Number of positions (securities)	2	3
12 Months or More | Other debt securities
Available-for-sale Securities [Abstract]
Number of positions (securities)	3	1
12 Months or More | Other equity securities
Available-for-sale Securities [Abstract]
Number of positions (securities)		0
12 Months or More | Obligations of other U.S. Government agencies and corporations
Held-to-maturity Securities [Abstract]
Number of positions (securities)	27	2
Available-for-sale Securities [Abstract]
Number of positions (securities)	1	0
12 Months or More | Obligations of states and political subdivisions
Held-to-maturity Securities [Abstract]
Number of positions (securities)	28	2
12 Months or More | Government agency mortgage backed securities | Residential mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	18	3
12 Months or More | Government agency mortgage backed securities | Commercial mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	3	0
12 Months or More | Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	18	4
12 Months or More | Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available-for-sale Securities [Abstract]
Number of positions (securities)	0	0