Subsequent event - Narrative (Details) - Subsequent event - Second Amended and Restated Credit Agreement	Apr. 05, 2019 USD ($)
Subsequent Event [Line Items]
Debt instrument term	5 years
Debt instrument, stated interest rate	2.00%
Maximum leverage ratio	4.50
Minimum interest coverage ratio	3.50
London Interbank Offered Rate (LIBOR) \| Minimum
Subsequent Event [Line Items]
Basis spread on variable rate	1.125%
London Interbank Offered Rate (LIBOR) \| Maximum
Subsequent Event [Line Items]
Basis spread on variable rate	2.00%
Federal Funds Effective Swap Rate
Subsequent Event [Line Items]
Basis spread on variable rate	0.50%
Adjusted LIBOR
Subsequent Event [Line Items]
Basis spread on variable rate	1.00%
Adjusted LIBOR \| Minimum
Subsequent Event [Line Items]
Basis spread on variable rate	0.125%
Adjusted LIBOR \| Maximum
Subsequent Event [Line Items]
Basis spread on variable rate	1.00%
Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 1,000,000,000.0
Term Loan
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 700,000,000.0

Debt Instrument, Covenant Terms, Maximum Leverage Ratio

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- Definition

Debt Instrument, Covenant Terms, Minimum Interest Coverage Ratio

+ References

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- 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

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-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

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

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