Goodwill and Other Intangibles - Other Intangible (Details) - USD ($) $ in Thousands	3 Months Ended	15 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Other Intangible Assets
Gross Carrying Amount	$ 42,134	$ 42,134	$ 42,456
Accumulated Amortization	28,265	28,265	28,416
Other intangible assets not subject to amortization	8,900	8,900
Amortization expense of other intangible assets	258	300
Trade names
Other Intangible Assets
Gross Carrying Amount	8,533	8,533	8,529
Trading rights
Other Intangible Assets
Gross Carrying Amount	339	339	339
Other
Other Intangible Assets
Gross Carrying Amount	50	50	50
POSIT trade name
Other Intangible Assets
Other intangible assets not subject to amortization	8,400	8,400
Customer related intangibles
Other Intangible Assets
Gross Carrying Amount	9,823	9,823	10,217
Accumulated Amortization	$ 5,908	5,908	6,219
Useful Lives	16 years 10 months 24 days
Proprietary software
Other Intangible Assets
Gross Carrying Amount	$ 23,389	23,389	23,321
Accumulated Amortization	$ 22,357	$ 22,357	$ 22,197
Useful Lives	8 years 3 months 18 days