Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	May. 29, 2015	May. 30, 2014	Feb. 28, 2015
Income Taxes [Line Items]
Income tax expense benefit computation description	The Corporation's provision for income taxes in interim periods is computed by applying its estimated annual effective tax rate against income before income tax expense for the period. In addition, non-recurring or discrete items are recorded during the period in which they occur.
Effective tax rate	34.60%	21.10%
Federal tax refund		$ 3.1
Tax on unrealized investment gains (losses) accounted for in other comprehensive income	$ (28.5)
Unrecognized tax benefits	21.7
Effect on income tax expense if unrecognized tax benefits are recognized	19.5
Decrease in unrecognized tax benefits	$ 2.3
Unrecognized tax benefits income tax penalties and interest accrued description	The Corporation recognizes interest and penalties accrued on unrecognized tax benefits and refundable income taxes as a component of income tax expense.
Interest and penalties on unrecognized tax expense and refundable income taxes	$ 0.2
Accrued Interest and penalties on unrecognized tax benefit	$ 3.0
Open tax years by major tax jurisdiction	The Corporation is subject to examination by the Internal Revenue Service for tax years 2010 to the present and various U.S. state and local jurisdictions for tax years 2001 to the present. The Corporation is also subject to tax examination in various international tax jurisdictions, including Canada, the United Kingdom, Australia, Italy, Mexico and New Zealand for tax years 2006 to the present.
Adjustments for Error Correction [Member]
Income Taxes [Line Items]
Reduction in income tax expense		$ 4.1	$ 4.1