Revenues - Summary of the Percentage of Total Revenues from Customers (Details) - Total Revenues - Customer concentration risk	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Express Scripts
Concentration Risk [Line Items]
Percentage of total revenues (as a percent)	76.00%	72.00%
McKesson
Concentration Risk [Line Items]
Percentage of total revenues (as a percent)	13.00%	18.00%

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.

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