Disposition - Prior Collaboration Agreement (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2009	Sep. 30, 2017	Sep. 24, 2016	Sep. 26, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration agreements revenue		$ 96.5	$ 235.4	$ 253.1
Grifols [Member] \| Blood screening [Member] \| Collaboration Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Manufacturing costs entitled to recover	50.00%
Share of Revenue from Any Assay	50.00%