Long-Term Debt 2018 Private Offering of Senior Notes (Details) - USD ($) $ in Millions	Jun. 30, 2020	May 01, 2020
Five Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty Eight [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.875%
Five Point Five Zero Zero Percentage Senior Notes Due Two Thousand Twenty Six [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		5.50%
Four Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty Three [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.875%
Senior Notes [Member] | Five Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty Eight [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 400
Debt Instrument, Interest Rate, Stated Percentage	5.875%
Senior Notes [Member] | Five Point Five Zero Zero Percentage Senior Notes Due Two Thousand Twenty Six [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		800
Debt Instrument, Interest Rate, Stated Percentage	5.50%
Senior Notes [Member] | Four Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 1,000
Debt Instrument, Interest Rate, Stated Percentage	4.85%