Fair Value Measurements (Schedule of Non-recurring Fair Value Measurements Of Long-Lived Assets Held For Sale) (Details) - Energy From Waste [Member] - Asset Actions [Member] - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Mar. 31, 2016
Discontinued Operation Long Lived Asset [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, Fair Value		$ 20.0
Long-lived assets held for sale, Total Loss	$ 20.0
Level 1 [Member] | Discontinued Operation Long Lived Asset [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, Fair Value		0.0
Level 2 [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, Fair Value		0.0
Level 3 [Member] | Discontinued Operation Long Lived Asset [Member]
Long Lived Assets Held-for-sale [Line Items]
Long-lived assets held for sale, Fair Value		$ 20.0