Investments (Details) - USD ($)	3 Months Ended
Apr. 30, 2020	Apr. 30, 2019	Jan. 31, 2020
Disclosure Text Block Supplement [Abstract]
Retained Earnings, Undistributed Earnings from Equity Method Investees	$ 10,000,000		$ 12,400,000
Proceeds from Equity Method Investment, Distribution	2,005,000	$ 0
Short-term Investments	$ 32,601,000		$ 26,073,000
Debt Securities, Held-to-Maturity, Weighted Average Yield, Maturity, Year One	1.30%		1.80%

Weighted average yield of investment in debt security measured at amortized cost (held-to-maturity) maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.

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Amount of consolidated retained earnings that represent undistributed (not yet received) earnings from 50% or less owned persons accounted for by the equity method (equity method investees).

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Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

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