Financial Instruments and Fair Value Measurements (Schedules of Concentration of Risk) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018	Dec. 28, 2018
Distributor Concentration Risk | Revenue from Contract with Customer Benchmark [Member] | Amerisource Bergen Corporation [Member]
Concentration Risk
Concentration Risk, Percentage		12.30%
Distributor Concentration Risk | Revenue from Contract with Customer Benchmark [Member] | CuraScript, Inc
Concentration Risk
Concentration Risk, Percentage	31.10%	35.90%	30.20%	35.70%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | Amerisource Bergen Corporation [Member]
Concentration Risk
Concentration Risk, Percentage			27.60%		25.70%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | McKesson Corporation [Member]
Concentration Risk
Concentration Risk, Percentage			14.10%		21.90%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | CuraScript, Inc
Concentration Risk
Concentration Risk, Percentage			10.30%		13.10%
Product Concentration Risk | Net Sales Attributable to Products | Acthar
Concentration Risk
Concentration Risk, Percentage	30.90%	36.30%	30.50%	34.70%
Product Concentration Risk | Net Sales Attributable to Products | Inomax
Concentration Risk
Concentration Risk, Percentage	18.40%	16.70%	18.10%	17.00%
Product Concentration Risk | Net Sales Attributable to Products | Ofirmev
Concentration Risk
Concentration Risk, Percentage	11.60%	10.90%	11.50%	10.70%