Debt and Interest Expense - Additional Information (Detail) (USD $)						12 Months Ended			12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Fair Value, Inputs, Level 2 [Member] Market Approach Valuation Technique [Member]	Dec. 31, 2012 Fair Value, Inputs, Level 2 [Member] Market Approach Valuation Technique [Member]	Dec. 31, 2013 Zero-Coupon Senior Notes due 2036	Dec. 31, 2006 Zero-Coupon Senior Notes due 2036	Dec. 31, 2012 Zero-Coupon Senior Notes due 2036	Dec. 31, 2013 5.750% Senior Notes due 2014	Dec. 31, 2012 5.750% Senior Notes due 2014	Dec. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Western Gas Partners, LP [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Minimum [Member] London Interbank Offered Rate (LIBOR) [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Minimum [Member] London Interbank Offered Rate (LIBOR) [Member] Western Gas Partners, LP [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Maximum [Member] London Interbank Offered Rate (LIBOR) [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Maximum [Member] London Interbank Offered Rate (LIBOR) [Member] Western Gas Partners, LP [Member]
Debt Instrument [Line Items]
Line of credit, maximum capacity											$ 5,000,000,000	$ 800,000,000
Loan proceeds upon issuing debt							500,000,000
Debt instrument, maturity date						Oct. 10, 2036			Jun. 15, 2014
Debt Instrument, face amount	15,202,000,000	14,952,000,000				2,360,000,000		2,360,000,000	275,000,000	275,000,000
Yield to maturity						5.24%
Debt instrument, accreted value	13,557,000,000	13,269,000,000	15,230,000,000			727,000,000
Debt instrument, stated interest rate									5.75%
Debt instrument, earliest call date						Oct. 10, 2014
Total borrowings, fair value				$ 15,300,000,000	$ 16,200,000,000
Line of credit, expiration date											Sep. 02, 2015	Mar. 24, 2016
Margin added to LIBOR													1.25%	1.30%	2.50%	1.90%
Percentage of capital stock of certain wholly owned foreign subsidiaries											65.00%