Recent Financing Transactions - EEGH (Details) - USD ($) $ in Millions	Sep. 30, 2021	Jun. 30, 2021	Jun. 29, 2021
EEGH
Debt Instrument [Line Items]
Face amount		$ 650	$ 2,250
EGTS
Debt Instrument [Line Items]
Face amount	$ 1,600	$ 1,600
EEGH 3.6% Senior Notes, due 2024 | EEGH
Debt Instrument [Line Items]
Face amount			450
EEGH 3% Senior Notes, due 2029 | EEGH
Debt Instrument [Line Items]
Face amount			600
EEGH 4.8% Senior Notes, due 2043 | EEGH
Debt Instrument [Line Items]
Face amount			400
EEGH 4.6% Senior Notes, due 2044 | EEGH
Debt Instrument [Line Items]
Face amount			500
EEGH 3.9% Senior Notes, due 2049 | EEGH
Debt Instrument [Line Items]
Face amount			$ 300
3.6% Senior Notes due 2024 | EEGH
Debt Instrument [Line Items]
Stated interest rate		3.60%
Face amount		$ 339
3.6% Senior Notes due 2024 | EGTS
Debt Instrument [Line Items]
Face amount		$ 111
3.0% Senior Notes due 2029 | EEGH
Debt Instrument [Line Items]
Stated interest rate		3.00%
Face amount		$ 174
3.0% Senior Notes due 2029 | EGTS
Debt Instrument [Line Items]
Face amount		$ 426
4.8% Senior Notes due 2043 | EEGH
Debt Instrument [Line Items]
Stated interest rate		4.80%
Face amount		$ 54
4.8% Senior Notes due 2043 | EGTS
Debt Instrument [Line Items]
Face amount		$ 346
4.6% Senior Notes due 2044 | EEGH
Debt Instrument [Line Items]
Stated interest rate		4.60%
Face amount		$ 56
4.6% Senior Notes due 2044 | EGTS
Debt Instrument [Line Items]
Face amount		$ 444
3.9% Senior Notes due 2049 | EEGH
Debt Instrument [Line Items]
Stated interest rate		3.90%
Face amount		$ 27
3.9% Senior Notes due 2049 | EGTS
Debt Instrument [Line Items]
Face amount		$ 273