Retirement and Savings Plans - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Nov. 30, 2012	Feb. 29, 2012
Defined Benefit Plan Disclosure [Line Items]
Number of defined contribution retirement plans	1
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Employer expected contribution to defined benefit plans		$ 1.5
Employer contribution made to defined benefit plan	1.1
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Employer expected contribution to defined benefit plans		0.1
Other Postretirement Benefit Plans, Defined Benefit | Maximum
Defined Benefit Plan Disclosure [Line Items]
Employer contribution made to defined benefit plan	$ 0.2