Income Taxes - New tax legislation (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Apr. 01, 2018 item	Dec. 31, 2017	Apr. 01, 2018 USD ($) item	Mar. 26, 2017	Mar. 27, 2016
Income Taxes
Federal statutory rate (as a percent)	21.00%	35.00%	31.30%	34.00%	34.00%
Income tax benefit to re-measure deferred tax liabilities \| $			$ 0.2
Maximum percentage of net interest expense deductible as a percent of adjusted taxable income			30.00%
Maximum percentage of net operating losses allowed as a percent of taxable income			80.00%
Number of tax returns under examination \| item	0		0

Number of federal, state and local income tax returns under examination.

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- Definition

Amount of reasonable estimate for income tax expense (benefit) from change in tax rate pursuant to Tax Cuts and Jobs Act of 2017 for which accounting for tax effect is incomplete.

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No definition available.

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- Definition

Maximum percentage of net interest expense deductible as a percent of adjusted taxable income pursuant to Tax Cuts and Jobs Act of 2017. Not yet effective as of balance sheet date.

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No definition available.

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- Definition

Maximum percentage of net operating losses allowed as a percent of taxable income pursuant to Tax Cuts and Jobs Act of 2017. Not yet effective as of balance sheet date.

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No definition available.

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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
-URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=65882285&loc=d3e32698-109319

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- References

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