Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2017
Effective income tax rate		60.00%	32.00%
Estimated loss contingency accrual expense	$ 210.0	$ 210.0
Tax benefit related to loss contingency accrual		$ 0.0
Impact of loss contingency accrual on ETR		23.00%
Impairment charges	46.5	$ 46.5
Deferred income tax asset recorded on non-deductible impairment expenses	17.4	$ 17.4
Effective income tax rate impacted for valuation allowance		5.00%
Uncertain tax positions	0.5	$ 0.5	$ 0.5
Positions of uncertain tax, if realized, would impact the effective tax rate	0.3	0.3	0.3
Accrued interest expense related to uncertain tax positions	0.0	0.0	$ 0.0
Forecast
Anticipated impact of loss contingency on ETR for the year				10.00%
Effective income tax rate impacted for valuation allowance				2.00%
U.S. Department of Justice
Estimated loss contingency accrual expense	$ 210.0	$ 210.0

This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the cost method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from estimated impairment losses.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to impairment loss.

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The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates.

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Amount of unrecognized tax benefits.

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Tax benefit related to loss contingency accrual.

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