Short-term Borrowings and Long-term Debt - Second Amended and Restated Credit Agreement, Interest Rates (Details) $ in Millions	Jun. 01, 2015 USD ($)
Credit Facility \| Second Amended And Restated Credit Agreement
Short-term Borrowings and Long-term Debt
Maximum borrowing capacity	$ 1,915.0
Credit Facility \| Term Loan A1
Short-term Borrowings and Long-term Debt
Maximum borrowing capacity	940.0
Credit Facility \| Term Loan A2
Short-term Borrowings and Long-term Debt
Maximum borrowing capacity	475.0
Credit Facility \| First Amendment To The Credit Agreement
Short-term Borrowings and Long-term Debt
Loan amendment fees	2.3
Revolver Credit Facility
Short-term Borrowings and Long-term Debt
Maximum borrowing capacity	500.0
Accordion maximum borrowing capacity	$ 600.0

Refers to a type of option that gives the company the right to increase its line of credit.

No definition available.

Name:	ks_LineOfCreditFacilityAccordionMaximumBorrowingCapacity
Namespace Prefix:	ks_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

+ Details

Name:	us-gaap_DebtIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=ks_SecondAmendedAndRestatedCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=ks_TermLoanA1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=ks_TermLoanA2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=ks_FirstAmendmentToCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: