Statements Of Consolidated and Combined Cash Flows - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Operating Activities    
Net Income $ 383.6  
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:    
Depreciation and amortization 98.7  
Deferred income taxes and investment tax credits 10.5  
Deferred revenue 0.4  
Equity-based compensation expense and profit sharing contribution 4.5  
Gain on sale of assets and impairment, net (52.0)  
Income from unconsolidated affiliates (44.2)  
Amortization of Financing Costs 0.3  
AFUDC equity (15.0)  
Distributions of earnings received from equity investees 44.1  
Changes in Assets and Liabilities:    
Accounts receivable 3.2  
Accounts receivable-affiliated 27.9  
Accounts payable 18.1  
Accounts payable-affiliated (20.3)  
Customer deposits (23.8)  
Taxes accrued (25.6)  
Exchange gas receivable/payable 0.4  
Other accruals (1.7)  
Prepayments and other current assets 20.1  
Regulatory assets/liabilities 43.7  
Postretirement and postemployment benefits (26.9)  
Deferred charges and other noncurrent assets (3.5)  
Other noncurrent liabilities (3.6)  
Net Cash Flows from Operating Activities 438.9  
Investing Activities    
Capital expenditures (775.9)  
Insurance recoveries 2.1  
Change in short-term lendings-affiliated (265.3)  
Proceeds from disposition of assets 55.0  
Contributions to equity investees (1.4)  
Distributions from equity investees 15.1  
Other investing activities (19.1)  
Net Cash Flows used for Investing Activities (989.5)  
Financing Activities    
Change in short-term borrowings 20.0  
Change in short-term borrowings-affiliated (245.0)  
Issuance of long-term debt-affiliated 0.0  
Payments of long-term debt-affiliated, including current portion (957.8)  
Proceeds from the issuance of common units, net of offering costs 1,168.4  
Distribution of IPO proceeds to parent (500.0)  
Contribution of capital from parent 1,217.3  
Quarterly distributions to unitholders 26.0  
Distribution to noncontrolling interest in Columbia OpCo (69.9)  
Net Cash Flows from Financing Activities 607.0  
Change in cash and cash equivalents 56.4  
Cash and cash equivalents at beginning of period 0.5  
Cash and Cash Equivalents at End of Period 56.9  
Predecessor    
Operating Activities    
Net Income   $ 204.7
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:    
Depreciation and amortization   87.7
Deferred income taxes and investment tax credits   69.5
Deferred revenue   2.3
Equity-based compensation expense and profit sharing contribution   4.4
Gain on sale of assets and impairment, net   (20.8)
Income from unconsolidated affiliates   (32.9)
Amortization of Financing Costs   0.0
AFUDC equity   (8.2)
Distributions of earnings received from equity investees   27.6
Changes in Assets and Liabilities:    
Accounts receivable   2.3
Accounts receivable-affiliated   19.6
Accounts payable   (0.4)
Accounts payable-affiliated   2.1
Customer deposits   75.2
Taxes accrued   (33.0)
Exchange gas receivable/payable   3.5
Other accruals   (0.1)
Prepayments and other current assets   26.8
Regulatory assets/liabilities   35.3
Postretirement and postemployment benefits   (15.9)
Deferred charges and other noncurrent assets   (3.9)
Other noncurrent liabilities   0.8
Net Cash Flows from Operating Activities   446.6
Investing Activities    
Capital expenditures   (527.4)
Insurance recoveries   6.8
Change in short-term lendings-affiliated   (34.6)
Proceeds from disposition of assets   5.9
Contributions to equity investees   (63.8)
Distributions from equity investees   0.0
Other investing activities   (5.5)
Net Cash Flows used for Investing Activities   (618.6)
Financing Activities    
Change in short-term borrowings   0.0
Change in short-term borrowings-affiliated   (378.9)
Issuance of long-term debt-affiliated   551.0
Payments of long-term debt-affiliated, including current portion   0.0
Proceeds from the issuance of common units, net of offering costs   0.0
Distribution of IPO proceeds to parent   0.0
Contribution of capital from parent   0.0
Quarterly distributions to unitholders   0.0
Distribution to noncontrolling interest in Columbia OpCo   0.0
Net Cash Flows from Financing Activities   172.1
Change in cash and cash equivalents   0.1
Cash and cash equivalents at beginning of period $ 0.5 0.3
Cash and Cash Equivalents at End of Period   $ 0.4