Fair Value of Financial Instruments (Cost and Equity Method Investments) (Narrative) (Details) $ in Thousands	3 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2016 USD ($)	Dec. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Other current liabilities	$ 43,459	$ 43,459	$ 43,459				$ 66,527
Assets, equity method investees	68,119	68,119	68,119				66,907
Credit Facility [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued	$ 292,800	$ 292,800	292,800				153,600
Other [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity in losses from unconsolidated affiliates			$ 4,400
Waha JVs [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investment, ownership percentage	33.00%	33.00%	33.00%
Waha JVs [Member] | Other [Member] | Interest Rate Swap [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity in losses from unconsolidated affiliates	$ 4,400		$ 4,400
Waha JVs [Member] | Equity Method Investee [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Equity method investment, aggregate cost						$ 6,000
Number of pipelines to be constructed						2
Equity method investments, equity contributions		$ 56,000
Equity method investment, equity contributions repaid	56,000
Waha JVs [Member] | Equity Method Investee [Member] | Credit Facility [Member] | Guarantee of Indebtedness of Others [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued	86,000	86,000	86,000		$ 78,000
Waha JVs [Member] | Equity Method Investee [Member] | Credit Facility [Member] | Guarantee of Indebtedness of Others [Member] | Subsequent Event [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued				$ 131,000
Waha JVs [Member] | Equity Method Investee [Member] | Credit Facility [Member] | Guarantee of Indebtedness of Others [Member] | Additional Letters of Credit [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued	8,000	8,000	8,000
Waha JVs [Member] | Equity Method Investee [Member] | Credit Facility [Member] | Guarantee of Indebtedness of Others [Member] | Additional Letters of Credit [Member] | Subsequent Event [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Letters of credit issued				$ 45,000
Waha JVs [Member] | Equity Method Investee [Member] | Interest Rate Swap [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Assets, equity method investees	4,000	4,000	4,000
Waha JVs [Member] | Equity Method Investee [Member] | Equity Contributions And/Or Loan Guarantees [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Unconsolidated affiliates, outstanding commitments						$ 78,000
Equity Method Investee [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Other current liabilities							32,400
Cost Method Investment [Member] | Cross Country Pipeline [Member] | Immediate Family Member of Management or Principal Owner [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Cost method investment, original cost	15,000	15,000	15,000
Fair Value Measurements, Non-Recurring [Member] | Carrying Amount [Member]
Fair Value, Financial Instruments Measured on a Non-Recurring Basis [Line Items]
Aggregate carrying value, cost and equity method investment assets	$ 16,700	$ 16,700	$ 16,700				$ 17,700