Annual report pursuant to Section 13 and 15(d)

Schedule I—Condensed Financial Information of Registrant - Footnotes - Narrative (Details)

v3.3.1.900
Schedule I—Condensed Financial Information of Registrant - Footnotes - Narrative (Details)
$ in Thousands
Dec. 31, 2015
USD ($)
mi
Dec. 31, 2014
USD ($)
May. 31, 2013
USD ($)
mi
Condensed Financial Statements, Captions [Line Items]      
Line of Credit Facility, Outstanding Borrowings $ 10,165,000 $ 8,985,500  
Creole Trail Pipeline [Member]      
Condensed Financial Statements, Captions [Line Items]      
Length of Natural Gas Pipeline | mi 94   94
CTPL Term Loan [Member]      
Condensed Financial Statements, Captions [Line Items]      
Line of Credit Facility, Unamortized Discount $ 1,429 2,435  
Line of Credit Facility, Outstanding Borrowings [1],[2] $ 400,000 $ 400,000  
Parent Company [Member] | Creole Trail Pipeline [Member]      
Condensed Financial Statements, Captions [Line Items]      
Length of Natural Gas Pipeline | mi 94    
Parent Company [Member] | CTPL Term Loan [Member]      
Condensed Financial Statements, Captions [Line Items]      
Line of Credit Facility, Maximum Borrowing Capacity $ 400,000    
Line of Credit Facility, Unamortized Discount     $ 10,000
Line of Credit Facility, Outstanding Borrowings $ 400,000    
[1] Matures on May 28, 2017, when the full amount of the outstanding principal obligations must be repaid.
[2] Variable interest rate, at CTPL’s election, is LIBOR or the base rate plus the applicable margin. CTPL has historically elected LIBOR loans, for which the applicable margin is 3.25% and is due and payable at the end of each LIBOR period.