Income Taxes (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)
Retained Earnings Adjustments [Line Items]
Unrecognized tax benefits	$ 0
Accounting Standards Update 2016-16 [Member]
Retained Earnings Adjustments [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax	5,100,000
Accounting Standards Update 2018-02 [Member]
Retained Earnings Adjustments [Line Items]
Cumulative Effect on Retained Earnings, Net of Tax	$ (22,700,000)