Summarized Financial Information for Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	$ 277,078		$ 236,959
Operating expenses	92,913		82,763
Depreciation and amortization expense	85,544		66,650
General and administrative expense	34,180		23,734
Other operating expense	1,805		91
Operating income (loss)	62,636		63,721
Income from unconsolidated affiliates	42,878		25,008
Capital expenditures	269,631		270,954
Total assets	8,349,113		6,851,414		7,917,446
Barnett
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	87,818		93,084
Operating expenses	25,220		23,939
Depreciation and amortization expense	25,302		23,915
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	37,296		45,230
Income from unconsolidated affiliates	0		0
Capital expenditures	6,015		21,004
Total assets	1,488,440		1,571,188
Eagle Ford
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	78,090		57,959
Operating expenses	15,838		14,400
Depreciation and amortization expense	15,036		10,087
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	47,216		33,472
Income from unconsolidated affiliates	0		0
Capital expenditures	77,483		81,916
Total assets	1,229,903		984,486
Haynesville
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	27,457		33,474
Operating expenses	10,090		11,315
Depreciation and amortization expense	20,307		19,286
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	(2,940)		2,873
Income from unconsolidated affiliates	0		0
Capital expenditures	3,650		7,785
Total assets	1,260,388		1,323,957
Marcellus
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	1,371		3,729
Operating expenses	916		2,597
Depreciation and amortization expense	907		123
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	(452)		1,009
Income from unconsolidated affiliates	40,532		25,246
Capital expenditures	6,455	[1]	184	[2]
Total assets	1,530,903		1,216,897
Niobrara
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	6,512		2,302
Operating expenses	2,298		1,544
Depreciation and amortization expense	1,387		719
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	2,827		39
Income from unconsolidated affiliates	0		0
Capital expenditures	30,658	[3]	11,526	[4]
Total assets	177,192		99,775
Utica
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	24,574		5,496
Operating expenses	8,418		2,546
Depreciation and amortization expense	4,034		1,200
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	12,122		1,750
Income from unconsolidated affiliates	526		(161)
Capital expenditures	95,638	[5]	65,756	[6]
Total assets	1,255,064		483,305
Mid-Continent
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	51,256		40,915
Operating expenses	17,909		18,204
Depreciation and amortization expense	10,601		8,598
General and administrative expense	0		0
Other operating expense	0		0
Operating income (loss)	22,746		14,113
Income from unconsolidated affiliates	1,820		(77)
Capital expenditures	17,022		38,996	[7]
Total assets	778,924		755,108
Corporate
Segment Reporting Information [Line Items]
Revenues, including revenue from affiliates	0		0
Operating expenses	12,224		8,218
Depreciation and amortization expense	7,970		2,722
General and administrative expense	34,180		23,734
Other operating expense	1,805		91
Operating income (loss)	(56,179)		(34,765)
Income from unconsolidated affiliates	0		0
Capital expenditures	32,710		43,787
Total assets	$ 628,299		$ 416,698

[1] Amount excludes $33.2 million for the Partnership’s share of capital expenditures included in investments in unconsolidated affiliates.

[2] Amount excludes $93.2 million for the Partnership’s share of capital expenditures included in investments in unconsolidated affiliates.

[3] Amount includes $16.0 million of capital expenditures attributable to noncontrolling interest owners.

[4] Amount includes $5.8 million of capital expenditures attributable to noncontrolling interest owners.

[5] Amount excludes $76.2 million for the Partnership’s share of capital expenditures included in investments in unconsolidated affiliates and includes $30.9 million of capital expenditures attributable to noncontrolling interest owners.

[6] Amount excludes $72.0 million for the Partnership’s share of capital expenditures included in investments in unconsolidated affiliates and includes $22.0 million of capital expenditures attributable to noncontrolling interest owners.

[7] Amount excludes $0.3 million for the Partnership’s share of capital expenditures included in investments in unconsolidated affiliates.