Debt and Interest Expense (Tables)

12 Months Ended

Dec. 31, 2016

Debt Instruments [Abstract]

Debt Outstanding and Debt Activity Tables

The following table presents WES and WGP’s outstanding debt as of December 31, 2016 and 2015:

	December 31, 2016						December 31, 2015
thousands	Principal		Carrying Value		Fair Value(1)		Principal		Carrying Value		Fair Value (1)
WGP RCF	$	28,000	$	28,000	$	28,000	$	—	$	—	$	—
2021 Notes	500,000		494,734		536,252		500,000		493,711		513,645
2022 Notes	670,000		668,634		681,723		670,000		668,432		595,744
2018 Notes	350,000		349,188		351,531		350,000		348,706		339,293
2044 Notes	600,000		593,132		615,753		400,000		389,707		321,499
2025 Notes	500,000		490,971		492,499		500,000		490,095		422,285
2026 Notes	500,000		494,802		518,441		—		—		—
WES RCF	—		—		—		300,000		300,000		300,000
Total long-term debt	$	3,148,000	$	3,119,461	$	3,224,199	$	2,720,000	$	2,690,651	$	2,492,466

⁽¹⁾  Fair value is measured using the market approach and Level 2 inputs.

12.  DEBT AND INTEREST EXPENSE (CONTINUED)

Debt activity. The following table presents WES and WGP’s debt activity for the years ended December 31, 2016 and 2015:

thousands	Carrying Value
Balance at December 31, 2014	$	2,409,935
WES RCF borrowings	400,000
Issuance of 2025 Notes	500,000
Repayments of WES RCF borrowings	(610,000		)
Repayment of WGP WCF borrowings	(1,150		)
Other	(8,134		)
Balance at December 31, 2015	$	2,690,651
WES RCF borrowings	600,000
Issuance of 2026 Notes	500,000
Issuance of 2044 Notes	200,000
Repayments of WES RCF borrowings	(900,000		)
WGP RCF borrowings	28,000
Other	810
Balance at December 31, 2016	$	3,119,461

Interest Expense Table

The following table summarizes the amounts included in interest expense:

	Year Ended December 31,
thousands	2016			2015			2014
Third parties
Long-term debt	$	122,428		$	102,058		$	81,495
Amortization of debt issuance costs and commitment fees	7,509			5,734			5,103
Capitalized interest	(5,562		)	(8,318		)	(9,832		)
Total interest expense – third parties	124,375			99,474			76,766
Affiliates
WGP WCF	—			2			3
Deferred purchase price obligation – Anadarko (1)	(7,747		)	14,398			—
Total interest expense – affiliates	(7,747		)	14,400			3
Interest expense	$	116,628		$	113,874		$	76,769

⁽¹⁾  See Note 2 for a discussion of the Deferred purchase price obligation - Anadarko.