Acquisitions | Acquisition & Integration Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	$ 29,748	$ 13,015	$ 101,931	$ 14,997
Professional services
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	10,694	3,978	37,702	5,305
Restructuring costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	6,861	0	24,188	0
Transaction related costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	1,925	8,535	19,154	9,190
Other
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	10,268	502	20,887	502
Americas
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	14,100	9,500	58,600	10,500
Americas | Restructuring costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	2,000		12,400
Europe
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	14,100	$ 3,500	40,400	$ 4,500
Europe | Restructuring costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	$ 4,900		$ 11,800