Income Taxes - Deferred Taxes (Details) (Details) (USD $) In Millions, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013
Deferred tax assets:
Allowance for doubtful accounts	$ 0.6	$ 0.7
Sundry accruals	2.3	2.8
Vacation accrual	5.1	5.2
Stock-based compensation	5.4	6.1
Payroll related accruals	4.6	3.3
Lease accruals	8.4	9.1
Investments	2.0us-gaap_DeferredTaxAssetsInvestments	1.9us-gaap_DeferredTaxAssetsInvestments
Net operating loss carryforwards	144.3	118.2
Tax credit carryforwards	6.5	5.1
Deferred revenue	2.4us-gaap_DeferredTaxAssetsDeferredIncome	2.4us-gaap_DeferredTaxAssetsDeferredIncome
Reserves and other	9.3	10.2
Gross deferred tax assets	190.9us-gaap_DeferredTaxAssetsGross	165.0us-gaap_DeferredTaxAssetsGross
Valuation allowance	(154.0)	(123.1)
Total deferred tax assets, net of valuation allowance	36.9us-gaap_DeferredTaxAssetsNet	41.9us-gaap_DeferredTaxAssetsNet
Deferred tax liabilities:
Unearned revenue	(35.8)	(35.8)
Other intangibles	(2.7)	(4.7)
Property and equipment, principally due to differences in depreciation	(6.5)	(7.7)
Other	(1.3)us-gaap_DeferredTaxLiabilitiesOther	(0.9)us-gaap_DeferredTaxLiabilitiesOther
Total deferred tax liabilities	(46.3)us-gaap_DeferredIncomeTaxLiabilities	(49.1)us-gaap_DeferredIncomeTaxLiabilities
Net deferred tax asset (liability)	$ (9.4)us-gaap_DeferredTaxAssetsLiabilitiesNet	$ (7.2)us-gaap_DeferredTaxAssetsLiabilitiesNet

Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Reserves and Other

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Deferred Tax Liabilities, Unearned Revenue

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Amount of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from investments (excludes investments in subsidiaries and equity method investments).

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The tax effect as of the balance sheet date of the amount of future tax deductions arising from all unused tax credit carryforwards which have been reduced by a valuation allowance.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensated absences (includes, but not limited to, sick and personal days).

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from accrued liabilities.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred rent.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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