Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2017

Asset Retirement Obligation Disclosure [Abstract]

Change in Asset Retirement Obligations

The following table summarizes the change in AROs. Amounts include conditional AROs.

(In thousands)		2017		2016
Balance at January 1,	$	26,886	$	24,360
Liabilities incurred		145		1,303
Accretion expense		1,359		1,269
Liabilities settled(a)		(1,789)		(110)
Revisions in estimated cash flows		137		64
Balance at December 31,	$	26,738	$	26,886

(a)In 2017, MGE removed asbestos at Blount for $1.6 million.