Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Senior Notes) (Details)

v3.10.0.1
Long-Term Debt (Senior Notes) (Details) - Senior Notes
$ in Millions
Sep. 30, 2018
USD ($)
Debt Instrument [Line Items]  
Aggregate unamortized premium $ 29.5
2021 Senior Notes  
Debt Instrument [Line Items]  
Interest rate 6.75%
2025 Senior Notes  
Debt Instrument [Line Items]  
Interest rate 6.875%