Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]
Cash paid for interest, net of amount capitalized	$ 329.6	$ 241.1	$ 250.4
Cash paid for income taxes, net of refunds	9.3	22.0
Cash received for income taxes, net of refund			(39.6)
Construction costs funded through accounts payable	177.1	1.8	4.7
Amortization of deferred revenue	39.9	55.7	56.5
Note reveivable received related to the sale of AMP Trillium	12.0	0.0	0.0
Capital assets received related to the sale of AMP Trillium	6.3	$ 0.0	$ 0.0
Restricted cash	$ 118.4