Partnership's Calculation of Net Income Per Unit for Common and Subordinated Limited Partner Units (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Earnings Per Unit [Line Items]
Net income attributable to Access Midstream Partners, L.P.	$ 69,213		$ 51,606		$ 128,751		$ 103,972
Less general partner interest in net income	(5,995)		(1,752)		(10,787)		(3,181)
Limited partner interest in net income	63,218		49,854		117,964		100,791
Weighted average limited partner units outstanding - basic and diluted
Weighted average limited partner units outstanding basic and diluted	177,749,514		148,353,783		172,651,841		148,353,168
Common Units
Earnings Per Unit [Line Items]
Limited partner interest in net income	19,116	[1]	26,641	[1]	32,563	[1]	53,860	[1]
Net income per limited partner unit - basic and diluted
Net income per unit - basic and diluted	$ 0.18		$ 0.34		$ 0.32		$ 0.68
Weighted average limited partner units outstanding - basic and diluted
Weighted average limited partner units outstanding basic and diluted	108,673,392		79,277,661		103,575,719		79,277,046
Subordinated Units
Earnings Per Unit [Line Items]
Limited partner interest in net income	21,721		23,213		41,558		46,931
Net income per limited partner unit - basic and diluted
Net income per unit - basic and diluted	$ 0.31		$ 0.34		$ 0.60		$ 0.68
Weighted average limited partner units outstanding - basic and diluted
Weighted average limited partner units outstanding basic and diluted	69,076,122		69,076,122		69,076,122		69,076,122
Convertible Class B Units
Earnings Per Unit [Line Items]
Limited partner interest in net income	10,755	[1]			20,985	[1]
Subordinated Class C Units
Earnings Per Unit [Line Items]
Limited partner interest in net income	$ 11,626	[1]			$ 22,858	[1]

[1] Adjusted to reflect amortization for the beneficial conversion feature.