CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash Generated From Operations
Net income	$ 75	$ 73
Depreciation	22	21
Amortization of debt issue costs reported as interest expense		1
Equity earnings from equity investments (Note 3 and 4)	(43)	(42)
Distributions received from operating activities of equity investments (Note 3)	31	41
Change in operating working capital (Note 9)	5	6
Total cash generated from operations	90	100
Investing Activities
Capital expenditures	(7)	(11)
Total investing activities	(11)	(208)
Financing Activities
Common unit issuance, net (Note 6)	71
Common unit issuance subject to rescission, net (Note 6)		19
Long-term debt issued, net of discount (Note 5)		195
Long-term debt repaid (Note 5)	(50)	(25)
Total financing activities	(69)	117
Increase/(decrease) in cash and cash equivalents	10	9
Cash and cash equivalents, beginning of year	50	39
Cash and cash equivalents, end of year	60	48
Class B units
Financing Activities
Distributions paid (Note 6)	(22)	(12)
Common units and General Partner interest combined
Financing Activities
Distributions paid (Note 8)	(68)	(60)
Great Lakes
Cash Generated From Operations
Equity earnings from equity investments (Note 3 and 4)	(17)	(15)
Investing Activities
Investment/Acquisition of interests	(4)	(4)
Portland Natural Gas Transmission System
Cash Generated From Operations
Equity earnings from equity investments (Note 3 and 4)	$ (7)	(9)
Investing Activities
Investment/Acquisition of interests		$ (193)