Common shareholder's equity, mezzanine equity, and non-controlling interests (Tables)

9 Months Ended

Sep. 30, 2018

Common shareholder's equity, mezzanine equity, and non-controlling interests

Schedule of additional paid-in surplus

	For the Three Months				For the Nine Months
	Ended September 30,				Ended September 30,
(Millions)	2018		2017		2018		2017
Reimbursement for performance shares	$	—	$	—	$	1.4	$	2.5
Reimbursement for retention bonuses		—		1.9		—		9.0
Total Additional paid-in surplus	$	—	$	1.9	$	1.4	$	11.5

Schedule of change in non-controlling interest

(Millions)	For the Three Months		For the Nine Months
	Ended September 30,		Ended September 30,
	2018		2018
Non-controlling interests	$	1.0	$	0.2
Net income attributable to non-controlling interests		0.3		0.9
Return of capital to non-controlling interests		(0.2)		—
Non-controlling interests as of September 30, 2018	$	1.1	$	1.1

(Millions)	For the Three Months		For the Nine Months
	Ended September 30,		Ended September 30,
	2017		2017
Non-controlling interests	$	250.2	$	251.3
Net income attributable to non-controlling interests		4.2		13.2
Dividends to non-controlling interests		(4.7)		(14.1)
Redemption of non-controlling interests		(250.0)		(250.0)
Other, net		—		(0.7)
Non-controlling interests as of September 30, 2017	$	(0.3)	$	(0.3)