Goodwill and Other Intangibles - Other Intangible (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Intangible Assets
Gross Carrying Amount	$ 41,742	$ 42,456
Accumulated Amortization	28,827	28,416
Other intangible assets not subject to amortization	8,900
Amortization expense of other intangible assets	1,010	1,276	$ 1,900
Estimate of future amortization expense for acquired other intangibles
Total	12,915	14,040	$ 15,390
Trade names
Other Intangible Assets
Gross Carrying Amount	8,521	8,529
Trading rights
Other Intangible Assets
Gross Carrying Amount	339	339
Other
Other Intangible Assets
Gross Carrying Amount	50	50
Estimate of future amortization expense for acquired other intangibles
2019	844
2020	643
2021	563
2022	563
2023	563
Thereafter	829
Total	4,005
POSIT trade name
Other Intangible Assets
Other intangible assets not subject to amortization	8,400
Customer related intangibles
Other Intangible Assets
Gross Carrying Amount	9,617	10,217
Accumulated Amortization	$ 6,282	6,219
Useful Lives	17 years
Proprietary software
Other Intangible Assets
Gross Carrying Amount	$ 23,215	23,321
Accumulated Amortization	$ 22,545	$ 22,197
Useful Lives	8 years 6 months