Retirement and Postretirement Benefit Plans - Summary of Fair Value of Defined Benefit Pension Plan Assets, Postretirement Benefit Plans (Detail) - Postretirement Benefit Plan [Member] - USD ($) $ in Thousands	Feb. 29, 2016	Feb. 28, 2015	Feb. 28, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	$ 40,210	$ 45,600	$ 48,757
Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	1,706	1,192
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	10,324	12,133
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	28,180	32,275
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	10,543	12,133
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	219
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	10,324	12,133
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	29,667	33,467
Level 2 [Member] | Short-term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	1,487	1,192
Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of defined benefit pension plan assets	$ 28,180	$ 32,275