Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Aug. 26, 2016	Aug. 28, 2015	Aug. 26, 2016	Aug. 28, 2015
Income Tax Disclosure [Abstract]
Effective tax rate	32.50%	21.00%	32.60%	31.70%
Unrecognized tax benefit due to the issuance of regulations that clarified the law and the expiration of statute		$ 4.3		$ 4.3
Tax on unrealized investment gains (losses) accounted for in other comprehensive income			$ 10.0	$ 22.0
Unrecognized tax benefits	$ 17.1		17.1
Effect on income tax expense if unrecognized tax benefits are recognized	15.4		15.4
Decrease in unrecognized tax benefits	1.4		1.4
Accrued Interest and penalties on unrecognized tax benefit	$ 1.8		1.8
Net expense for Interest and penalties on unrecognized tax benefits and refundable income taxes			$ 0.2