Selected Quarterly Financial Data (unaudited), Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
Dec. 26, 2017	Mar. 28, 2017	Dec. 26, 2017
Income tax
Income tax (expense) benefit, net tax legislation, revalue of deferred tax balances and foreign operations	$ 3.1		$ 3.1
Earnings per share basic and diluted, related to new tax legislation, revaluation of deferred tax balances and foreign operations	$ 0.04		$ 0.04
Legal settlement
Legal settlement
Legal settlement expense, after tax		$ 9.2
Earnings per share, basic and diluted (in dollars per share)		$ (0.13)

The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109260490&loc=d3e1337-109256

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration