Debt and Interest Expense (tables)

9 Months Ended

Sep. 30, 2014

The following table presents WES’s outstanding debt as of September 30, 2014, and December 31, 2013:



	September 30, 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	$	495,576	$	557,828	$	500,000	$	495,173	$	533,615
4.000% Senior Notes due 2022	670,000		673,017		690,811		670,000		673,278		641,237
WES revolving credit facility	170,000		170,000		170,000		—		—		—
2.600% Senior Notes due 2018	350,000		350,506		355,311		250,000		249,718		247,988
5.450% Senior Notes due 2044	400,000		393,815		437,573		—		—		—
Total debt outstanding	$	2,090,000	$	2,082,914	$	2,211,523	$	1,420,000	$	1,418,169	$	1,422,840


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

Debt activity. The following table presents WES’s debt activity for the nine months ended September 30, 2014:



thousands	Carrying Value
Balance at December 31, 2013	$	1,418,169
Revolving credit facility borrowings	650,000
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	(480,000		)
Other	(5,255		)
Balance at September 30, 2014	$	2,082,914

The following table summarizes the amounts included in interest expense:



	Three Months Ended September 30,						Nine Months Ended September 30,
thousands	2014			2013			2014			2013
Interest expense on long-term debt	$	21,671		$	14,994		$	59,251		$	43,783
Amortization of debt issuance costs and commitment fees	1,107			1,135			3,799			3,252
Capitalized interest	(1,900		)	(3,111		)	(7,347		)	(9,552		)
Interest expense	$	20,878		$	13,018		$	55,703		$	37,483