Derivative Instrument and Hedging Activities 1 Narrative (Details) (USD $)	0 Months Ended	12 Months Ended
	Nov. 01, 2011	Dec. 31, 2011
Derivative [Line Items]
Derivative Net Liability Position Aggregate Fair Value		$ 22,900,000
Year 2013 [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount		5,560,000
Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative Notional Amount		525,000,000
Derivative Description Of Variable Rate Basis	three-month LIBOR plus a credit spread of 3.0175 percent
Derivative Ineffectiveness		no swap ineffectiveness
Derivative Fixed Interest Rate		3.63%
Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months		12,400,000
Interest Rate Swaps [Member] | LNG Holdings [Member]
Derivative [Line Items]
Derivative Notional Amount		455,000,000
Treasury Rate Locks [Member]
Derivative [Line Items]
Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months		571,000
Natural Gas Price Swaps [Member] | Gathering And Processing [Member]
Derivative [Line Items]
Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months		4,000,000
Natural Gas Price Swaps [Member] | Gathering And Processing [Member] | MMBtus [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount		3,660,000
Natural Gas Price Swaps [Member] | Distribution [Member] | Year 2012 [Member] | MMBtus [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount		19,400,000
NGL Price Swaps [Member] | Gathering And Processing [Member]
Derivative [Line Items]
Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months		$ 4,000,000
NGL Price Swaps [Member] | Gathering And Processing [Member] | MMBtus [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount		5,490,000
NGL Price Swaps [Member] | Gathering And Processing [Member] | Gallons [Member]
Derivative [Line Items]
Derivative Nonmonetary Notional Amount		65,378,124