Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2016

Supplemental Cash Flow Information [Abstract]

Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]

The following table discloses information about investing and financing activities that affected recognized assets and liabilities but did not result in cash receipts or payments.  Also disclosed in the table iscash paid for interest, net of interest capitalized, and cash paid for income taxes, net of income tax refunds.

Year ended December 31 (In millions)	2016			2015			2014
NON-CASH INVESTING AND FINANCING ACTIVITIES
Power plant long-term service agreement	$	39.5		$	2.3		$	—
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid during the period for
Interest (net of interest capitalized) (A)	$	141.9		$	145.4		$	150.8
Income taxes (net of income tax refunds)	(5.9		)	(3.4		)	0.2

(A) Net of interest capitalized of$7.5 million, $4.2 millionand$2.4 millionin2016, 2015and2014, respectively.