Fair Value of Financial Instruments (Assets and Liabilites Measured on a Non-Recurring Basis) (Cost and Equity Investees) (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended	7 Months Ended	12 Months Ended
	Jan. 31, 2017	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2015
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Unrecognized unrealized fair market value gains, equity investee, net of tax				$ 3,952,000	$ 0	$ 0
Recognized unrealized loss, unconsolidated affiliates				(3,528,000)	7,978,000	269,000
Equity investee, net contributions				31,000,000	58,100,000	$ 1,100,000
Net investment in equity investees, liability			$ 1,983,956,000	2,079,498,000	1,983,956,000
Credit Facility [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued			292,800,000	$ 314,300,000	292,800,000
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investee, ownership percentage				33.00%
Cost Method Investment [Member] | CCP [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Cost method investment, original cost				$ 15,000,000
Equity Investee [Member] | Pacer [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Number of joint ventures				2
Construction projects, percentage complete				100.00%
Equity Investee [Member] | Pacer [Member] | Canadian Dollars [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Recognized unrealized loss, unconsolidated affiliates		$ (3,600,000)
Aggregate net carrying value, equity investee, other current assets			28,800,000	$ 31,400,000	28,800,000
Equity Investee [Member] | Pacer [Member] | Canadian Dollars [Member] | Equity Investees, Remaining Amounts Committed [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Unconsolidated affiliates, outstanding commitments				$ 0
Equity Investee [Member] | Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity investee, aggregate initial cost							$ 6,000,000
Number of pipelines to be constructed				2
Equity investee, equity and other contributions				$ 27,000,000
Equity investee, net contributions			0
Revenue, related parties				245,000,000
Receivables including retainage, net of BIEC, related parties				71,200,000
Aggregate net carrying value, equity investee, other current assets				6,000,000
Net investment in equity investees, liability			4,000,000		4,000,000
Equity Investee [Member] | Waha JVs [Member] | Interest Rate Swaps [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Unrecognized unrealized fair market value gains, equity investee				6,400,000
Unrecognized unrealized fair market value gains, equity investee, net of tax				4,000,000
Recognized unrealized loss, unconsolidated affiliates					4,400,000
Equity Investee [Member] | Waha JVs [Member] | Credit Facility [Member] | Commercial and/or Financial Standby [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued			$ 78,000,000	$ 91,000,000	$ 78,000,000
Equity Investee [Member] | Joint Venture Which Was Liquidated in 2016 [Member] | Pacer [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Number of joint ventures				1
Subsequent Event [Member] | Equity Investee [Member] | Pacer [Member] | Canadian Dollars [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Other equity investee, proceeds related to ongoing liquidation	$ 12,000,000