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Income Taxes - Components of net deferred tax assets (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Income taxes |  |
Balance carryforwards, gross value | $ 275.9 | $ 304.4
Deferred tax assets, future tax benefits | 70.6 | 303.9
Valuation allowance | (11.4) | (15.7)
Charitable contribution and capital loss |  |
Income taxes |  |
Charitable contributions and capital loss, gross value |  | 21.7
Deferred tax assets, charitable contributions and capital loss |  | 8.6
Valuation allowance |  | (2.1)
Foreign tax authority |  |
Income taxes |  |
Tax credit carryforward, amount | 0.0 | 0.0
Deferred tax asset, federal foreign tax credit | 9.7 | 13.5
Tax credit carryforward, valuation allowance | (9.7) | (13.5)
Domestic tax authority |  |
Income taxes |  |
Tax credit carryforward, amount | 0.0 | 0.0
Deferred tax assets, tax credit carryforwards | 39.3 | 259.6
Tax credit carryforward, valuation allowance | (1.7) | (0.1)
State and local jurisdiction |  |
Income taxes |  |
Tax credit carryforward, amount | 0.0 | 0.0
Operating loss carryforwards, gross value | 275.9 | 282.7
Deferred tax assets, tax credit carryforwards | 4.6 | 5.0
Deferred tax asset, state net operating loss | 17.0 | 17.2
Tax credit carryforward, valuation allowance | 0.0 | 0.0
Operating loss carryforwards, valuation allowance | $ 0.0 | $ 0.0

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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign tax credit carryforwards. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
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