Shareholders' Equity - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Feb. 14, 2018	Jun. 06, 2016
2016 Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized repurchase amount						$ 150,000,000
Amount repurchased (in shares)	512,943	123,082	671,409	267,811
Amount repurchased	$ 31,600,000	$ 6,800,000	$ 41,200,000	$ 13,900,000
Average repurchase price (in dollars per share)	$ 61.63	$ 55.61	$ 61.30	$ 51.93
2018 Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized repurchase amount					$ 200,000,000.0