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Segment Information (Concentration Risk by Customer) (Details) - Sales revenue, net [Member] - Customer concentration risk [Member] | 12 Months Ended
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Dec. 29, 2017 | Dec. 30, 2016 | Jan. 01, 2016
Diplomat Specialty Pharmacy [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk | 18.00% | 33.00% | 83.00%
Caremark L.L.C. [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk | 16.00% | 9.00% | 0.00%
Ipsen [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk | 15.00% | 17.00% | 0.00%
Accredo Health, Incorporated [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk | 11.00% | 9.00% | 0.00%
Affiliates of McKesson Corporation [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk | 11.00% | 7.00% | 0.00%

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