Commitments and contingencies - Schedule of Future Minimum Payments (Details) $ in Thousands	Dec. 31, 2016 USD ($)
Minimum payments for property leases
Loss Contingencies [Line Items]
Less than 1 year	$ 33,655
1 to 5 years	98,938
5 plus years	49,551
Total	182,144
Minimum payments for hosting services
Loss Contingencies [Line Items]
Less than 1 year	50,959
1 to 5 years	48,927
5 plus years	0
Total	99,886
Minimum payments for other leases
Loss Contingencies [Line Items]
Less than 1 year	4,197
1 to 5 years	4,912
5 plus years	0
Total	$ 9,109