Transactions with Major Customers and Affiliates (Tables)

12 Months Ended

Dec. 31, 2016

Transactions with Major Customers and Affiliates [Abstract]

Schedule of revenue by major customers

Operating revenues received from three of our major customers in 2016, 2015 and 2014 are as follows (in millions):

	2016		2015		2014
Duke Energy Corporation	$	178.9	$	94.6	$	91.5
National Grid	166.3		129.6		91.2
Public Service Enterprise Group	143.6		110.2		115.3