Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income Available for Common Stock	$ 132,392	$ 77,774
Other Comprehensive Income, Before Tax:
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	163,132	48,021
Reclassification Adjustment for Realized (Gains) Losses on Derivative Financial Instruments in Net Income	162,588	311
Other Comprehensive Income, Before Tax	325,720	48,332
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	44,649	13,230
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Derivative Financial Instruments in Net Income	44,500	86
Income Taxes – Net	89,149	13,316
Other Comprehensive Income	236,571	35,016
Comprehensive Income	$ 368,963	$ 112,790