Description of business and summary of significant accounting policies (Tables)

12 Months Ended

Oct. 01, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Fair Value, Assets Measured on Recurring Basis

The following financial assets and liabilities were measured at fair value on a recurring basis using the type of inputs indicated below and are as follows (amounts in millions):

	Fair Value Measurements Using:
	Total		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs
October 1, 2017
Investment in marketable securities	$	1.3	$	1.3	$	—	$	—
October 2, 2016
Investment in marketable securities	$	1.3	$	1.3	$	—	$	—

Earnings Per Share

Earnings per share for 2017, 2016 and 2015 were calculated as follows (amounts in millions, except per share data):

	Fiscal Years
	2017		2016			2015
Basic
Net (loss) income	$	176.3	$	(32.6	)	$	84.6
Weighted-average common shares outstanding	114.9		107.0			94.2
Basic (loss) earnings per share	$	1.54	$	(0.31	)	$	0.90
Diluted
Net (loss) income	$	176.3	$	(32.6	)	$	84.6
Weighted-average common shares outstanding for basic	114.9		107.0			94.2
Dilutive effect of stock awards	2.2		—			1.7
Weighted-average common shares outstanding on a diluted basis	117.1		107.0			95.9
Diluted (loss) earnings per share	$	1.51	$	(0.31	)	$	0.88