Debt and Interest Expense (tables)

3 Months Ended

Mar. 31, 2014

Debt Instruments [Abstract]

Debt Outstanding and Debt Activity Tables

The following table presents WES’s outstanding debt as of March 31, 2014, and December 31, 2013:

	March 31, 2014						December 31, 2013
thousands	Principal		Carrying Value		Fair Value(1)		Principal		Carrying Value		Fair Value (1)
5.375% Senior Notes due 2021	$	500,000	$	495,305	$	548,287	$	500,000	$	495,173	$	533,615
4.000% Senior Notes due 2022	670,000		673,192		666,755		670,000		673,278		641,237
2.600% Senior Notes due 2018	350,000		350,567		352,159		250,000		249,718		247,988
5.450% Senior Notes due 2044	400,000		393,775		406,664		—		—		—
Total debt outstanding	$	1,920,000	$	1,912,839	$	1,973,865	$	1,420,000	$	1,418,169	$	1,422,840

⁽¹⁾  Fair value is measured using Level 2 inputs.

Debt activity. The following table presents the debt activity for the three months ended March 31, 2014:

thousands	Carrying Value
Balance at December 31, 2013	$	1,418,169
Revolving credit facility borrowings	430,000
Issuance of 5.450% Senior Notes due 2044	400,000
Issuance of 2.600% Senior Notes due 2018	100,000
Repayments of revolving credit facility	(430,000		)
Other	(5,330		)
Balance at March 31, 2014	$	1,912,839

Interest Expense Table

The following table summarizes the amounts included in interest expense:

	Three Months Ended   March 31,
thousands	2014			2013
Interest expense on long-term debt	$	16,135		$	13,939
Amortization of debt issuance costs and commitment fees	1,266			1,053
Capitalized interest	(3,440		)	(3,181		)
Interest expense	$	13,961		$	11,811