BUSINESS COMBINATIONS BUSINESS COMBINATIONS - YEAR ENDED JANUARY 31, 2018 - PURCHASE PRICE ALLOCATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Schedule of Purchase Price Allocations for the Year Ended January 31, 2018 [Line Items]
Goodwill	$ 1,388,299	$ 1,264,818	$ 1,207,176
Individually Insignificant Business Combinations - Year Ended January 31, 2018
Schedule of Purchase Price Allocations for the Year Ended January 31, 2018 [Line Items]
Payment Made At Closing To Acquire Businesses	106,049
Fair value of contingent obligation	27,605
Post-closing purchase price adjustment	2,380
Business Combination, Consideration Transferred	136,034
Accounts receivable	4,184
Other current assets, including cash acquired	15,108
Other assets	2,765
Current and other liabilities	(12,462)
Deferred Revenue - Current and Long-Term	4,424
Deferred Income Taxes	8,660
Net Tangible Assets (Liabilities)	(3,489)
Identifiable intangible assets	57,718
Goodwill	81,805
Total Purchase Price Allocations	136,034
Customer Relationships | Individually Insignificant Business Combinations - Year Ended January 31, 2018
Schedule of Purchase Price Allocations for the Year Ended January 31, 2018 [Line Items]
Identifiable intangible assets	24,444
Acquired Technology | Individually Insignificant Business Combinations - Year Ended January 31, 2018
Schedule of Purchase Price Allocations for the Year Ended January 31, 2018 [Line Items]
Identifiable intangible assets	30,952
Trademarks and Trade Names | Individually Insignificant Business Combinations - Year Ended January 31, 2018
Schedule of Purchase Price Allocations for the Year Ended January 31, 2018 [Line Items]
Identifiable intangible assets	$ 2,322