Related Party Transactions (Tables)

9 Months Ended

Sep. 30, 2016

Related Party Transactions [Abstract]

Schedule of Related Party Transactions [Table Text Block]

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
	(In thousands)
Indirect charges:
Operating and maintenance expenses	$	10,580	$	10,441	$	31,039	$	28,128
Selling, general and administrative expenses	2,292		1,929		6,205		6,199
Total indirect charges	$	12,872	$	12,370	$	37,244	$	34,327