	December 31,			December 31,
	2012			2011
SHORT-TERM DEBT
Credit Facilities (1):
PAA senior secured hedged inventory facility, bearing a weighted-average interest rate of 1.6% and 1.5% at December 31, 2012 and December 31, 2011, respectively	$	665		$	75
PAA senior unsecured revolving credit facility, bearing a weighted-average interest rate of 2.4% and 1.6% at December 31, 2012 and December 31, 2011, respectively (2)	92			32
PNG senior unsecured revolving credit facility, bearing a weighted-average interest rate of 2.1% at both December 31, 2012 and December 31, 2011 (3)	77			68
5.63% senior notes due December 2013 (4)	250			—
4.25% senior notes due September 2012 (5)	—			500
Other	2			4
Total short-term debt	1,086			679

LONG-TERM DEBT
Senior Notes:
5.63% senior notes due December 2013 (4)	—			250
5.25% senior notes due June 2015	150			150
3.95% senior notes due September 2015	400			400
5.88% senior notes due August 2016	175			175
6.13% senior notes due January 2017	400			400
6.50% senior notes due May 2018	600			600
8.75% senior notes due May 2019	350			350
5.75% senior notes due January 2020	500			500
5.00% senior notes due February 2021	600			600
3.65% senior notes due June 2022	750			—
2.85% senior notes due January 2023	400			—
6.70% senior notes due May 2036	250			250
6.65% senior notes due January 2037	600			600
5.15% senior notes due June 2042	500			—
4.30% senior notes due January 2043	350			—
Unamortized discounts	(15		)	(13		)
Senior notes, net of unamortized discounts	6,010			4,262
Credit Facilities and Other:
PNG senior unsecured revolving credit facility, bearing a weighted-average interest rate of 2.1% at both December 31, 2012 and December 31, 2011 (3)	105			54
PNG GO Bond term loans, bearing a weighted-average interest rate of 1.5% at both December 31, 2012 and December 31, 2011	200			200
Other	5			4
Total long-term debt	6,320			4,520
Total debt (2) (3) (6)	$	7,406		$	5,199

(1) During 2012 and 2011, we renewed, extended or refinanced our principal bank credit facilities, including PNG’s credit facility. See “Credit Facilities” below for further discussion.

(2) We classify as short-term certain borrowings under our PAA senior unsecured revolving credit facility. These borrowings are primarily designated as working capital borrowings, must be repaid within one year and are primarily for hedged NGL and crude oil inventory and NYMEX and ICE margin deposits.

(3) PNG classifies as short-term debt any borrowings under the PNG senior unsecured revolving credit facility that have been designated as working capital borrowings and must be repaid within one year. Such borrowings are primarily related to a portion of PNG’s hedged natural gas inventory.

(4) Our $250 million 5.63% senior notes will mature in December 2013 and are thus classified as short-term at December 31, 2012.

(5) Our $500 million 4.25% senior notes matured in September 2012 and were repaid with proceeds from our credit facilities. The proceeds from the issuance of these senior notes were used to supplement capital available from our hedged inventory facility, to fund working capital needs associated with base levels of waterborne cargos and for seasonal NGL inventory requirements. After the maturity of these senior notes, we are now using our expanded credit facilities for such purposes.

(6) Our fixed-rate senior notes (including current maturities) had a face value of approximately $6.3 billion and $4.8 billion as of December 31, 2012 and 2011, respectively. We estimated the aggregate fair value of these notes as of December 31, 2012 and 2011 to be approximately $7.3 billion and $5.4 billion, respectively. Our fixed-rate senior notes are traded among institutions, and these trades are routinely published by a reporting service. Our determination of fair value is based on reported trading activity near year end. We estimate that the carrying value of outstanding borrowings under our credit facilities and agreements approximates fair value as interest rates reflect current market rates. The fair value estimates for both our senior notes and credit facilities are based upon observable market data and are classified within Level 2 of the fair value hierarchy.