Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Information [Abstract]
Number of reportable segments	4
Segment Reporting Information [Line Items]
Revenues	$ 1,397.8	$ 1,645.8	$ 5,885.7
Operating Margin	174.2	190.0
Total assets	5,148.5	3,698.4	5,105.0
Capital Expenditures	206.9	98.3
Depreciation and amortization expenses	(64.0)	(47.4)
General and administrative expenses	(36.3)	(34.9)
Interest expense, net	(32.1)	(30.5)
Income tax expense	(9.4)	(10.1)
Other, net	1.4	2.1
Net income	33.8	69.2	159.3
Field Gathering and Processing [Member]
Segment Reporting Information [Line Items]
Revenues	332.2	374.0
Operating Margin	53.8	73.0
Total assets	2,854.7	1,661.1
Capital Expenditures	96.1	26.2
Coastal Gathering and Processing [Member]
Segment Reporting Information [Line Items]
Revenues	230.3	283.6
Operating Margin	23.5	46.3
Total assets	416.3	422.5
Capital Expenditures	6.5	2.0
Logistics Assets [Member]
Segment Reporting Information [Line Items]
Revenues	117.5	108.4
Operating Margin	56.3	43.0
Total assets	1,210.7	823.0
Capital Expenditures	103.7	60.1
Marketing and Distribution [Member]
Segment Reporting Information [Line Items]
Revenues	1,291.4	1,581.2
Operating Margin	34.0	26.1
Total assets	436.9	507.9
Capital Expenditures	0	9.1
Other Segment [Member]
Segment Reporting Information [Line Items]
Revenues	6.6	1.4
Operating Margin	6.6	1.4
Total assets	21.4	49.5
Capital Expenditures	0	0
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(580.2)	(703.1)
Operating Margin	0	0
Total assets	134.2	123.1
Capital Expenditures	0.6	0.6
TRC Non- Partnership [Member]
Segment Reporting Information [Line Items]
Revenues	0	0.3
Operating Margin	0	0.2
Total assets	74.3	111.3
Capital Expenditures	0	0.3
Natural gas sales [Member]
Segment Reporting Information [Line Items]
Sale of commodities	255.3	202.9
NGL sales [Member]
Segment Reporting Information [Line Items]
Sale of commodities	963.5	1,290.2
Condensate sales [Member]
Segment Reporting Information [Line Items]
Sale of commodities	27.1	29.0
Petroleum Products [Member]
Segment Reporting Information [Line Items]
Sale of commodities	31.3	45.5
Derivative activities [Member]
Segment Reporting Information [Line Items]
Sale of commodities	6.5	2.2
Fractionating and treating fees [Member]
Segment Reporting Information [Line Items]
Fees from midstream services	29.7	26.9
Storage And Terminaling Fees [Member]
Segment Reporting Information [Line Items]
Fees from midstream services	60.2	30.5
Gas gathering and processing fees [Member]
Segment Reporting Information [Line Items]
Fees from midstream services	18.5	8.6
Total Other Revenues [Member]
Segment Reporting Information [Line Items]
Fees from midstream services	5.7	10.0
Total outside Revenues [Member]
Segment Reporting Information [Line Items]
Sale of commodities	1,283.7	1,569.8
Fees from midstream services	114.1	76.0
Revenues	1,397.8	1,645.8
Total outside Revenues [Member] | Field Gathering and Processing [Member]
Segment Reporting Information [Line Items]
Sale of commodities	38.1	45.4
Fees from midstream services	20.2	10.9
Revenues	58.3	56.3
Total outside Revenues [Member] | Coastal Gathering and Processing [Member]
Segment Reporting Information [Line Items]
Sale of commodities	69.6	59.8
Fees from midstream services	8.8	3.7
Revenues	78.4	63.5
Total outside Revenues [Member] | Logistics Assets [Member]
Segment Reporting Information [Line Items]
Sale of commodities	32.9	45.7
Fees from midstream services	47.1	38.7
Revenues	80.0	84.4
Total outside Revenues [Member] | Marketing and Distribution [Member]
Segment Reporting Information [Line Items]
Sale of commodities	1,136.5	1,417.2
Fees from midstream services	38.0	22.7
Revenues	1,174.5	1,439.9
Total outside Revenues [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Sale of commodities	6.6	1.4
Fees from midstream services	0	0
Revenues	6.6	1.4
Total outside Revenues [Member] | Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Sale of commodities	0	0
Fees from midstream services	0	0
Revenues	0	0
Total outside Revenues [Member] | TRC Non- Partnership [Member]
Segment Reporting Information [Line Items]
Sale of commodities	0	0.3
Fees from midstream services	0	0
Revenues	0	0.3
Total Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Sale of commodities	0	0
Fees from midstream services	0	0
Revenues	0	0
Total Intersegment Revenues [Member] | Field Gathering and Processing [Member]
Segment Reporting Information [Line Items]
Sale of commodities	273.0	317.4
Fees from midstream services	0.9	0.3
Revenues	273.9	317.7
Total Intersegment Revenues [Member] | Coastal Gathering and Processing [Member]
Segment Reporting Information [Line Items]
Sale of commodities	151.9	220.0
Fees from midstream services	0	0.1
Revenues	151.9	220.1
Total Intersegment Revenues [Member] | Logistics Assets [Member]
Segment Reporting Information [Line Items]
Sale of commodities	0.9	0
Fees from midstream services	36.6	24.0
Revenues	37.5	24.0
Total Intersegment Revenues [Member] | Marketing and Distribution [Member]
Segment Reporting Information [Line Items]
Sale of commodities	110.5	132.0
Fees from midstream services	6.4	9.3
Revenues	116.9	141.3
Total Intersegment Revenues [Member] | Other Segment [Member]
Segment Reporting Information [Line Items]
Sale of commodities	0	0
Fees from midstream services	0	0
Revenues	0	0
Total Intersegment Revenues [Member] | Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Sale of commodities	(536.3)	(669.4)
Fees from midstream services	(43.9)	(33.7)
Revenues	(580.2)	(703.1)
Total Intersegment Revenues [Member] | TRC Non- Partnership [Member]
Segment Reporting Information [Line Items]
Sale of commodities	0	0
Fees from midstream services	0	0
Revenues	$ 0	$ 0