General - Recent Accounting Pronouncements (Details) $ in Millions	9 Months Ended
Sep. 30, 2017 USD ($)
Maximum \| Adoption of revenue recognition ASUs \| Retrospective early adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effective adjustment on Health Insurer Fee revenue	$ 40.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration