Equity-Based Compensation - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended		0 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Management Incentive Compensation Plan	Jun. 30, 2014 Access Midstream Long-Term Incentive Plan	Sep. 30, 2014 Access Midstream Long-Term Incentive Plan	Jul. 16, 2014 Minimum	Sep. 30, 2014 Minimum	Sep. 30, 2014 Minimum Access Midstream Long-Term Incentive Plan	Jul. 16, 2014 Maximum	Sep. 30, 2014 Maximum	Sep. 30, 2014 Maximum Access Midstream Long-Term Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period								1 year	4 years		4 years	5 years
Stock-based compensation expense	$ 83.6	$ 5.8	$ 107.4	$ 22.2	$ 41.1	$ 38.5	$ 41.0
Cash payments to MICP participants	88.8
Common units to be awarded							3.5
Unrecognized compensation expense attributable to LTIP							$ 45.8
Unrecognized compensation expense attributable to LTIP expected recognition period										1 year			4 years