Industry Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fee revenue and other income:
Fee income from customers		$ 25,374	$ 22,771
Interest income	[1]	11,975	11,420
Interest expense		679	480
Intersegment income (expense)
Tax-equivalized pre-tax income	[1]	10,488	9,393
Goodwill		12,569	11,590	$ 12,569
Other intangible assets, net		1,885	2,971
Total assets		1,650,802	1,447,006	$ 1,657,209
Funding Sources		1,240,746	1,164,430
Information Services [Member]
Fee revenue and other income:
Fee income from customers		24,872	22,324
Interest income	[1]	5,516	4,728
Interest expense
Intersegment income (expense)
Tax-equivalized pre-tax income	[1]	6,734	5,455
Goodwill		12,433	11,454
Other intangible assets, net		1,885	2,971
Total assets		878,199	747,301
Funding Sources		644,909	564,376
Banking Services [Member]
Fee revenue and other income:
Fee income from customers		376	324
Interest income	[1]	5,750	5,886
Interest expense		679	480
Intersegment income (expense)		462	300
Tax-equivalized pre-tax income	[1]	3,425	3,457
Goodwill		136	136
Other intangible assets, net
Total assets		858,283	715,753
Funding Sources		595,837	600,054
Corporate Eliminations and Other [Member]
Fee revenue and other income:
Fee income from customers		126	123
Interest income	[1]	709	806
Interest expense
Intersegment income (expense)		(462)	(300)
Tax-equivalized pre-tax income	[1]	329	481
Goodwill
Other intangible assets, net
Total assets		(85,680)	(16,048)
Funding Sources

[1] Presented on a tax-equivalent basis assuming a tax rate of 21% for 2018 and 35% for 2017. The tax-equivalent adjustment was approximately $687,000 and $1,421,000 for the First Quarter of 2018 and 2017, respectively.