Planned Maintenance Outages (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Cost of sales
Planned Maintenance Outage
Planned maintenance outage costs	$ 6.6	$ 8.6

Represents the planned maintenance outage costs incurred by the entity.

No definition available.

Name:	ks_PlannedMaintenanceOutageCosts
Namespace Prefix:	ks_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration