Long-Term Debt - Schedule of Maturities of Long-term Debt (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2015
Maturities of Long-term Debt [Abstract]
Total debt, carrying amount		$ 670.0
2018		25.0
2019		30.0
2020		35.0
2021		280.0
Thereafter		300.0
Interest expense-amortization of deferred financing costs (less than)	$ 0.2	1.8	$ 2.0	$ 2.7
Senior Debt
Maturities of Long-term Debt [Abstract]
Total debt, carrying amount		370.0
2018		25.0
2019		30.0
2020		35.0
2021		280.0
Thereafter		0.0
Convertible Debt
Maturities of Long-term Debt [Abstract]
Total debt, carrying amount		300.0
2018		0.0
2019		0.0
2020		0.0
2021		0.0
Thereafter		$ 300.0