Derivatives and Hedging Activities (Tables)

6 Months Ended

Mar. 31, 2016

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Fair Value and Balance Sheet Classification

Although management is not aware of any factors that would materially affect the estimated fair value amounts presented below, such amounts have not been comprehensively revalued for purposes of these financial statements since the dates shown, and therefore, estimates of fair value subsequent to those dates may differ significantly from the amounts presented below.

		March 31, 2016				September 30, 2015
	Level in Fair Value Hierarchy	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
		(In thousands)
Financial assets
Cash and cash equivalents	1	$	276,084	$	276,084	$	284,049	$	284,049
Available-for-sale securities
Equity securities	1	101,591		101,591		101,952		101,952
Obligations of U.S. government	2	264,544		264,544		482,464		482,464
Obligations of states and political subdivisions	2	27,335		27,335		27,123		27,123
Corporate debt securities	2	506,269		506,269		505,800		505,800
Mortgage-backed securities
Agency pass-through certificates	2	1,105,016		1,105,016		1,160,518		1,160,518
Other commercial MBS	2	92,331		92,331		102,706		102,706
Total available-for-sale securities		2,097,086		2,097,086		2,380,563		2,380,563
Held-to-maturity securities	2
Mortgage-backed securities
Agency pass-through certificates	2	1,558,087		1,564,349		1,643,216		1,637,420
Total held-to-maturity securities		1,558,087		1,564,349		1,643,216		1,637,420
Loans receivable	3	9,545,322		10,059,040		9,170,634		9,667,750
FDIC indemnification asset	3	13,480		12,803		16,275		15,522
FHLB and FRB stock	2	113,187		113,187		107,198		107,198
Other assets - interest rate contracts	2	17,498		17,498		11,879		11,879
Financial liabilities
Customer accounts	2	10,543,384		9,671,338		10,631,703		10,004,290
FHLB advances	2	1,980,000		2,086,109		1,830,000		1,938,384
Other liabilities - interest rate contracts	2	17,498		17,498		11,879		11,879
Other liabilities - commercial loan hedge	2	2,329		2,329		966		966
Other liabilities - long term borrowing hedge	2	25,242		25,242		14,555		14,555

The following table presents the fair value and balance sheet classification of derivatives at March 31, 2016 and September 30, 2015:

	Asset Derivatives						Liability Derivatives
	March 31, 2016			September 30, 2015			March 31, 2016			September 30, 2015
	Balance Sheet			Balance Sheet			Balance Sheet			Balance Sheet
	Location	Fair Value		Location	Fair Value		Location	Fair Value		Location	Fair Value
	(In thousands)
Interest rate contracts	Other assets	$	17,498	Other assets	$	11,879	Other liabilities	$	17,498	Other liabilities	$	11,879
Commercial loan hedge	Other assets	—		Other assets	—		Other liabilities	2,329		Other liabilities	966
Long term borrowing hedge	Other assets	—		Other assets	—		Other liabilities	25,242		Other liabilities	14,555
		$	17,498		$	11,879		$	45,069		$	27,400