Income Tax Income Tax Disclosure	6 Months Ended
Jul. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax Disclosure	INCOME TAXES The Company’s effective tax rate varies from the federal statutory rate primarily due to state and local taxes, research and development tax credit, tax benefits on qualified production activities, and tax-exempt insurance premiums. The Company’s effective tax rates for the three- and six-month periods ended July 31, 2017 were 29.2% and 30.5%, respectively. The decrease in the effective tax rate in the second quarter of fiscal 2018 compared to the year-to-date fiscal 2018 effective tax rate is primarily due to the recognition of discrete tax expense related to the Company's adoption of ASU 2016-09 in the fiscal 2018 first quarter as further discussed in Note 2 Summary of Significant Accounting Policies. This ASU requires that the tax effects resulting from the settlement of stock-based awards be recognized as a discrete income tax expense or benefit in the income statement in the reporting period in which they occur. The Company’s effective tax rates for the three- and six-month periods ended July 31, 2016 were 30.7% and 30.7%, respectively. The decrease in the effective tax rate in the three- and six-month periods ended July 31, 2017 compared to July 31, 2016 is primarily due to a higher estimate of the research and development tax credit in the current year compared to the prior year.

Income Tax Income Tax Disclosure

6 Months Ended

Jul. 31, 2017

INCOME TAXES

The Company’s effective tax rate varies from the federal statutory rate primarily due to state and local taxes, research and development tax credit, tax benefits on qualified production activities, and tax-exempt insurance premiums. The Company’s effective tax rates for the three- and six-month periods ended July 31, 2017 were 29.2% and 30.5%, respectively. The decrease in the effective tax rate in the second quarter of fiscal 2018 compared to the year-to-date fiscal 2018 effective tax rate is primarily due to the recognition of discrete tax expense related to the Company's adoption of ASU 2016-09 in the fiscal 2018 first quarter as further discussed in Note 2 Summary of Significant Accounting Policies. This ASU requires that the tax effects resulting from the settlement of stock-based awards be recognized as a discrete income tax expense or benefit in the income statement in the reporting period in which they occur. The Company’s effective tax rates for the three- and six-month periods ended July 31, 2016 were 30.7% and 30.7%, respectively. The decrease in the effective tax rate in the three- and six-month periods ended July 31, 2017 compared to July 31, 2016 is primarily due to a higher estimate of the research and development tax credit in the current year compared to the prior year.