Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Accounting Policies [Abstract]

Schedule of Cash and Cash Equivalents [Table Text Block]

The following table provides a reconciliation of cash, cash equivalents, restricted cash and restricted cash equivalents reported in our consolidated balance sheets to the total shown in our consolidated statement of cash flows:

(In millions)	As of
	March 31, 2018		December 31, 2017		March 31, 2017		December 31, 2016
Cash and cash equivalents	$	11.5	$	8.2	$	11.1	$	14.6
Restricted cash and cash equivalents	368.5		255.6		316.7		224.7
Total cash, cash equivalents, restricted cash and restricted cash equivalents	$	380.0	$	263.8	$	327.8	$	239.3

Cash Flow, Supplemental Disclosures [Text Block]

The following table reconciles the consolidated statement of cash flows line items impacted by the adoption of this standard on January 1, 2018:

(In millions)	For the Three Months Ended March 31, 2017
	Adjusted			ASU 2016-18 Adjustment		Previously Reported
Decrease (increase) in restricted cash and cash equivalents	$	—		$	92.0	$	(92.0	)
Net cash used in investing activities	(274.4		)	92.0		(366.4		)
Net increase (decrease) in cash, cash equivalents, restricted cash and restricted cash equivalents	88.5			92.0		(3.5		)
Cash, cash equivalents, restricted cash and restricted cash equivalents beginning of period	239.3			224.7		14.6
Cash, cash equivalents, restricted cash and restricted cash equivalents end of period	$	327.8		$	316.7	$	11.1