Supplemental Guarantor Information (Narrative) (Details)	6 Months Ended
	Jun. 30, 2019
Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate	6.875%
Maturity year	2022
Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Interest rate	5.875%
Maturity year	2025
Senior Notes Due 2027 [Member]
Debt Instrument [Line Items]
Interest rate	6.75%
Maturity year	2027