Income Taxes - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
AMT Credits
Tax Credit Carryforward [Line Items]
Tax benefits released	$ 16.3
Accrued Interest Associated With Previous Uncertain Tax Positions
Tax Credit Carryforward [Line Items]
Tax benefits released	3.1
Gain On Divestitures - State Income Taxes
Tax Credit Carryforward [Line Items]
Unrecognized tax benefits	$ 0.5