CONSOLIDATED STATEMENTS OF CAPITALIZATION - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Secured Long-term debt:
Total Secured Long-term debt	$ 10,915,054	$ 10,619,826
Obligations under finance leases	68,876	75,649
Obligation under Rocky Mountain transactions	27,701	26,861
Patronage capital and membership fees	1,130,423	1,072,642
Subtotal	12,142,054	11,794,978
Less: long-term debt and finance leases due within one year	(281,238)	(208,649)
Less: unamortized debt issuance costs	(95,883)	(102,914)
Less: unamortized bond discounts on long-term debt	(16,025)	(16,651)
Total capitalization	11,748,908	11,466,764
Federal Financing Bank (FFB) | First mortgage notes payable to the Federal Financing Bank at interest rates varying from 1.03% to 8.21% (average rate of 3.39% at December 31, 2021) due in quarterly installments through 2046
Secured Long-term debt:
Total Secured Long-term debt	2,601,365	2,430,810
Federal Financing Bank (FFB) | First mortgage notes payable to the Federal Financing Bank at interest rates varying from 1.44% to 3.87% (average rate of 2.80% at December 31, 2021) due in quarterly installments through 2044
Secured Long-term debt:
Total Secured Long-term debt	3,925,493	3,554,205
Public | First mortgage bonds payable: Series 2006 First Mortgage Bonds, 5.534%, due 2031 through 2035
Secured Long-term debt:
Total Secured Long-term debt	300,000	300,000
Public | First mortgage bonds payable: Series 2007 First Mortgage Bonds, 6.191%, due 2024 through 2031
Secured Long-term debt:
Total Secured Long-term debt	500,000	500,000
Public | First mortgage bonds payable: Series 2009B First Mortgage Bonds, 5.95%, due 2039
Secured Long-term debt:
Total Secured Long-term debt	400,000	400,000
Public | First mortgage bonds payable: Series 2009 Clean renewable energy bond, 1.81%, due 2024
Secured Long-term debt:
Total Secured Long-term debt	3,031	4,041
Public | First mortgage bonds payable: Series 2010A First Mortgage Bonds, 5.375% due 2040
Secured Long-term debt:
Total Secured Long-term debt	450,000	450,000
Public | First mortgage bonds payable: Series 2011A First Mortgage Bonds, 5.25% due 2050
Secured Long-term debt:
Total Secured Long-term debt	300,000	300,000
Public | First mortgage bonds payable: Series 2012A First Mortgage Bonds, 4.20% due 2042
Secured Long-term debt:
Total Secured Long-term debt	250,000	250,000
Public | First mortgage bonds payable: Series 2014A First Mortgage Bonds, 4.55% due 2044
Secured Long-term debt:
Total Secured Long-term debt	250,000	250,000
Public | First mortgage bonds payable: Series 2016A First Mortgage Bonds, 4.25% due 2046
Secured Long-term debt:
Total Secured Long-term debt	250,000	250,000
Public | First Mortgage Bonds Payable: Series 2018A First Mortgage Bonds, 5.05% Due 2048
Secured Long-term debt:
Total Secured Long-term debt	500,000	500,000
Public | First Mortgage Bonds Payable Series 2020A First Mortgage Bonds, 3.75% Due 2048
Secured Long-term debt:
Total Secured Long-term debt	450,000	450,000
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: 2009A Heard and Monroe, and 2009B Monroe, Weekly rate bonds, fully redeemed through August 2021
Secured Long-term debt:
Total Secured Long-term debt	0	112,055
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: 2010A Burke and Monroe, and 2010B Burke, Weekly rate bonds, fully redeemed August 2021
Secured Long-term debt:
Total Secured Long-term debt	0	133,550
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: 2013A Appling, Burke and Monroe, Term rate bonds, 1.50% through April 1, 2020, due 2038 through 2040
Secured Long-term debt:
Total Secured Long-term debt	212,760	212,760
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: Series 2017 A Burke, Heard, Monroe and 2017B Burke, Indexed put bonds - weekly reset, 1.2% due 2040 through 2045
Secured Long-term debt:
Total Secured Long-term debt	122,620	122,620
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: Series 2017 C, D Burke, Remarketed in 2018 to fixed rate bonds, 4.125%, due 2041 through 2045
Secured Long-term debt:
Total Secured Long-term debt	200,000	200,000
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: Series 2017E Burke, Remarketed in 2018 to term rate bonds, 3.25% through February 3, 2025, due 2041 through 2045
Secured Long-term debt:
Total Secured Long-term debt	100,000	100,000
Georgia Development Authorities | First mortgage notes issued in connection with the sale of pollution control revenue bonds: Series 2017 F Burke, Remarketed in 2018 to term rate bonds, 3.00% through February 1, 2023, due 2041 through 2045
Secured Long-term debt:
Total Secured Long-term debt	$ 99,785	$ 99,785