Subsequent Events (Details) - LTG - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2019	Sep. 30, 2018
Subsequent Event [Line Items]
Equity percentage currently owned in equity interest		32.50%
Subsequent Event | Scenario, Forecast
Subsequent Event [Line Items]
Remaining equity interest percentage to be acquired	67.50%
Consideration paid for acquisition	$ 305
Long-term assumed in acquisition	166
Subsequent Event | Scenario, Forecast | LTG
Subsequent Event [Line Items]
Long-term assumed in acquisition	130
Subsequent Event | Scenario, Forecast | Thompsons
Subsequent Event [Line Items]
Long-term assumed in acquisition	$ 36