Fair Value of Financial Instruments (Schedule) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Weighted Average
Fair Value of Financial Instruments (Details) [Line Items]
Interest rate (in percentage)	3.80%
Significant Unobservable Inputs (Level 3)
Fair Value of Financial Instruments (Details) [Line Items]
Notes payable, fair value	$ 87.2
Senior Notes | Significant Unobservable Inputs (Level 3) | Senior Notes Due 2027
Fair Value of Financial Instruments (Details) [Line Items]
Long-term debt, fair value	246.7
Senior Notes | Significant Unobservable Inputs (Level 3) | Senior Notes Due 2026
Fair Value of Financial Instruments (Details) [Line Items]
Long-term debt, fair value	195.0
Senior Notes | Significant Other Observable Inputs (Level 2) | Senior Notes Due 2024
Fair Value of Financial Instruments (Details) [Line Items]
Long-term debt, fair value	260.4
Senior Notes | Significant Other Observable Inputs (Level 2) | Senior Notes Due 2023
Fair Value of Financial Instruments (Details) [Line Items]
Long-term debt, fair value	$ 269.3