For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Segment Reporting - Narrative (Details) - Segment	12 Months Ended
Segment Reporting - Narrative (Details) - Segment	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Concentration Risk [Line Items]
Number of operating segments	3
Aetna Inc. \| Customer Concentration Risk \| Revenues
Concentration Risk [Line Items]
Concentration risk, percentage ("Less than" - 2018 Federal Government)			9.80%
US Federal Government \| Customer Concentration Risk \| Revenues
Concentration Risk [Line Items]
Concentration risk, percentage ("Less than" - 2018 Federal Government)	14.00%	13.00%	10.00%