Intangible Assets Intangible Assets (Tables) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 87,664		$ 87,664
Finite-Lived Intangible Assets, Accumulated Amortization	8,729	$ 8,729	8,218
Intangible Assets, Net (Excluding Goodwill)	78,935		79,446
Database Rights [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	3,680		4,918
Finite-Lived Intangible Assets, Accumulated Amortization	3,656		2,521
Finite-Lived Intangible Assets, Net	2,151		2,397
Service Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	3,611		3,680
Finite-Lived Intangible Assets, Accumulated Amortization	2,183		3,640
Finite-Lived Intangible Assets, Net	24		40
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,125		3,611
Finite-Lived Intangible Assets, Accumulated Amortization	123		1,965
Finite-Lived Intangible Assets, Net	1,428		1,646
Noncompete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,918		1,125
Finite-Lived Intangible Assets, Accumulated Amortization	2,767		92
Finite-Lived Intangible Assets, Net	1,002		1,033
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
Other Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	0
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)	663		663
Indefinite-Lived License Agreements	$ 663		$ 663