Stock-based compensation - Narrative (Details)	3 Months Ended
Sep. 30, 2016 shares
Equity Incentive Plan 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs withheld for taxes in net share settlements (in shares)	232,000
Additional shares authorized (in shares)	1,666,666
RSU awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (shares)	728,000
Vested in period (shares)	651,000
Performance-based Restricted Stock Units \| Performance Share Program 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants in period (shares)	106,000
Vested in period (shares)	0
Cancelled in period (shares)	36,000
Performance-based Restricted Stock Units \| Performance Share Program 2015 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement period	15 months
Award vesting percentage	0.00%
Performance-based Restricted Stock Units \| Performance Share Program 2015 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance measurement period	21 months
Award vesting percentage	100.00%

Share-based Compensation by Share-based Payment Award, Performance Measurement Period

No definition available.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- 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.

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- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

+ References

No definition available.

+ Details

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- Definition

Percentage of vesting of share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

+ References

No definition available.

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