Acquisitions | Acquisition & Integration Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	$ 30,117	$ 1,982	$ 72,183	$ 1,982
Professional services
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	15,101		27,008
Restructuring costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	6,982		17,327
Transaction related costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	2,050		17,229
Other
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	5,984		10,619
Americas
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	14,300	1,100	44,400	1,100
Americas | Restructuring costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	900		10,400
Europe
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	14,700	$ 900	26,200	$ 900
Europe | Restructuring costs
Acquisition and integration expenses
Acquisition, integration and restructuring expenses	$ 6,100		$ 6,900