Industry Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fee revenue and other income:
Income from customers									$ 79,907	$ 76,572	$ 71,138
Intersegment income (expense)
Net interest income (expense) after provision for loan losses:
Income from customers									37,299	38,245	40,385
Intersegment income (expense)
Depreciation and amortization									3,096	2,896	2,532
Income tax expense	1,902	2,013	1,958	1,886	1,582	1,533	2,106	2,013	7,759	7,234	7,887
Net income	5,786	6,401	6,035	5,811	5,254	6,138	6,073	6,032	24,033	23,497	23,303
Goodwill	11,590				11,590				11,590	11,590	11,590
Other intangible assets, net	2,762				3,222				2,762	3,222	3,757
Total assets	1,500,731				1,326,020				1,500,731	1,326,020	1,287,387
Information Services [Member]
Fee revenue and other income:
Income from customers									78,773	75,010	70,376
Intersegment income (expense)									9,210	9,637	9,478
Net interest income (expense) after provision for loan losses:
Income from customers									15,678	15,986	18,547
Intersegment income (expense)									12	11	24
Depreciation and amortization									2,795	2,638	2,392
Income tax expense									3,006	2,232	2,802
Net income									16,379	15,237	15,761
Goodwill	11,454				11,454				11,454	11,454	11,454
Other intangible assets, net	2,762				3,222				2,762	3,222	3,757
Total assets	782,844				657,604				782,844	657,604	642,623
Banking Services [Member]
Fee revenue and other income:
Income from customers									1,134	1,216	1,272
Intersegment income (expense)									1,504	1,479	1,663
Net interest income (expense) after provision for loan losses:
Income from customers									21,621	22,259	21,838
Intersegment income (expense)									(12)	(11)	(24)
Depreciation and amortization									182	143	101
Income tax expense									4,753	5,002	5,085
Net income									7,654	8,133	8,014
Goodwill	136				136				136	136	136
Other intangible assets, net
Total assets	755,400				679,357				755,400	679,357	668,648
Corporate Eliminations and Other [Member]
Fee revenue and other income:
Income from customers										346	(510)
Intersegment income (expense)									(10,714)	(11,116)	(11,141)
Net interest income (expense) after provision for loan losses:
Income from customers
Intersegment income (expense)
Depreciation and amortization									119	115	39
Income tax expense
Net income										127	(472)
Goodwill
Other intangible assets, net
Total assets	$ (37,513)				$ (10,941)				$ (37,513)	$ (10,941)	$ (23,884)