Goodwill (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill [Abstract]

Schedule of Goodwill [Table Text Block]

Goodwill by segment is as follows for both March 31, 2018 and December 31, 2017 (in thousands):

Electric	$	243,558
Natural gas	114,028
Total	$	357,586