Changes in Benefit Obligations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
May 31, 2012	May 31, 2011
Postretirement Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of year	$ 9,103	$ 7,936
Service cost		5
Interest cost	416	439
Benefit payments	(665)	(633)
Medicare subsidy received	69	97
Actuarial (gains) losses	754	1,259
Benefit Obligation at End of Year	9,677	9,103
Postretirement Benefits, Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation at beginning of year	17,557	14,974
Service cost	745	709
Interest cost	968	891
Benefit payments	(369)	(317)
Actuarial (gains) losses	6,979	(33)
Currency exchange rate changes	(1,363)	1,333
Benefit Obligation at End of Year	$ 24,517	$ 17,557

The net increase or decrease of changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.

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+ Details

- Definition

1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date.

+ References

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+ Details

- Definition

The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

+ References

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+ Details