Income Taxes	3 Months Ended
Jul. 31, 2011
Income Taxes [Abstract]
Income Taxes	Note O — Income Taxes Income tax expense increased $8.4 million in the three months ended July 31, 2011, resulting in an increase in the effective tax rate to 33.2 percent, compared to 31.3 percent in the first quarter of 2011. The effective tax rate in the three months ended July 31, 2010, benefited from a favorable federal income tax determination related to a prior year, a higher domestic manufacturing deduction, and lower state income tax expense relative to the three months ended July 31, 2011. During the three months ended July 31, 2011, the effective income tax rate varied from the U.S. statutory income tax rate primarily due to the domestic manufacturing deduction partially offset by state income taxes. Within the next twelve months, it is reasonably possible that the Company could decrease its unrecognized tax benefits by an additional $1.1 million, primarily as a result of expiring statute of limitations periods.

Income Taxes

3 Months Ended

Jul. 31, 2011

Note O — Income Taxes

Income tax expense increased $8.4 million in the three months ended July 31, 2011, resulting in an increase in the effective tax rate to 33.2 percent, compared to 31.3 percent in the first quarter of 2011. The effective tax rate in the three months ended July 31, 2010, benefited from a favorable federal income tax determination related to a prior year, a higher domestic manufacturing deduction, and lower state income tax expense relative to the three months ended July 31, 2011.

During the three months ended July 31, 2011, the effective income tax rate varied from the U.S. statutory income tax rate primarily due to the domestic manufacturing deduction partially offset by state income taxes.

Within the next twelve months, it is reasonably possible that the Company could decrease its unrecognized tax benefits by an additional $1.1 million, primarily as a result of expiring statute of limitations periods.