Retirement and Postretirement Benefits Plans - Components of Net Periodic Benefit Cost and Changes Recognized Other Comprehensive Income, Pension Plans (Detail) (Pension Plans [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2011
Pension Plans [Member]
Components of net periodic benefit cost:
Service cost	$ 1,369	$ 1,106	$ 957
Interest cost	7,394	8,353	8,757
Expected return on plan assets	(6,473)	(6,858)	(6,588)
Amortization of transition obligation	7	6	6
Amortization of prior service cost	240	240	178
Amortization of actuarial loss	3,514	2,126	133
Settlements			(3)
Net periodic benefit cost	6,051	4,973	3,440
Other changes in plan assets and benefit obligations recognized in other comprehensive income:
Actuarial loss	5,657	14,996	1,175
Prior service cost	231	924	198
Amortization of prior service cost	(240)	(240)	(178)
Amortization of actuarial loss	(3,514)	(2,126)	(133)
Amortization of transition obligation	(7)	(6)	(6)
Settlements			3
Total recognized in other comprehensive income	2,127	13,548	1,059
Total recognized in net periodic benefit cost and other comprehensive income	$ 8,178	$ 18,521	$ 4,499