Supplemental Guarantor Condensed Consolidating Financial Statements - Guarantor Narrative (Details)	Dec. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Mar. 31, 2017
Debt Instrument [Line Items]
Ownership in Subsidiary, Percentage	100.00%
6.625% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.625%
6.625% Notes [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%
6.50% Notes [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%			6.50%
6.25% Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			6.25%
6.25% Notes Due 2026 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.25%
6.25% Notes due 2025 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.25%			6.25%