Intangible Assets Intangible Assets (Tables) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 93,860		$ 87,664
Finite-Lived Intangible Assets, Accumulated Amortization	10,070	$ 10,070	8,218
Intangible Assets, Net (Excluding Goodwill)	83,790		79,446
Database Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,918		4,918
Finite-Lived Intangible Assets, Accumulated Amortization	2,890		2,521
Finite-Lived Intangible Assets, Net	2,028		2,397
Service Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	3,680		3,680
Finite-Lived Intangible Assets, Accumulated Amortization	3,663		3,640
Finite-Lived Intangible Assets, Net	17		40
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	8,914		3,611
Finite-Lived Intangible Assets, Accumulated Amortization	3,327		1,965
Finite-Lived Intangible Assets, Net	5,587		1,646
Contract-Based Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	0		0
Finite-Lived Intangible Assets, Accumulated Amortization	0		0
Finite-Lived Intangible Assets, Net	0		0
Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	266
Finite-Lived Intangible Assets, Accumulated Amortization	51
Finite-Lived Intangible Assets, Net	215
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,125		1,125
Finite-Lived Intangible Assets, Accumulated Amortization	139		92
Finite-Lived Intangible Assets, Net	986		1,033
Insurance Contracts Acquired in Business Combination [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	0		0
Indefinite-lived Intangible Assets (Excluding Goodwill)	73,667		73,667
Indefinite-Lived License Agreements	73,667		73,667
Trademarks and Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	0		0
Indefinite-lived Intangible Assets (Excluding Goodwill)	1,290		663
Indefinite-Lived License Agreements	$ 1,290		$ 663