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Income Taxes - Schedule of Reconciliation of Beginning and Ending Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions | 12 Months Ended
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Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2017
Income Tax Disclosure [Abstract] |  |  |
Unrecognized tax benefits at the beginning of year | $ 24.9 | $ 25.2 | $ 24.2
Gross increases - current year tax positions | 2.2 | 0.6 | 0.7
Gross increases - prior year tax positions | 0.5 | 2.4 | 0.7
Gross increases - acquisitions | 2.3 |  |
Gross decreases - prior year tax positions | (0.1) | (3.3) |
Gross decreases - settlements | (2.7) |  |
Gross decreases - statute lapse | (5.4) |  | (0.4)
Unrecognized tax benefits at end of year | 21.7 | 24.9 | 25.2
Interest and penalties in year-end balance | $ 0.8 | $ 1.5 | $ (0.9)

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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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