Commitments and Contingencies - Employment Agreements (Details) $ in Millions	1 Months Ended
Mar. 31, 2015 USD ($)
Commitments and Contingencies
Charges in connection with termination of employment agreement	$ 3.8
Non-cash expenses related to stock award compensation	$ 0.8

Represents the amount of non-cash expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a severance arrangement.

No definition available.

Name:	int_SeveranceCostsNonCash
Namespace Prefix:	int_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration