Grant Agreement (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Apr. 30, 2013
Grant Agreement
Maximum grant receivable related to retention and expansion of workforce		$ 11.0
Proceeds from grant related to retention and expansion of workforce	$ 5.0

Represents the maximum amount of grant the entity is entitled to receive related to the retention and expansion of its workforce under the grant agreement.

No definition available.

Name:	incy_GrantReceivableRelatedToRetentionAndExpansionOfWorkforceMaximum
Namespace Prefix:	incy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant