Derivative and Hedging Activities (Tables)

12 Months Ended

Sep. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair value of financial instruments by balance sheet grouping

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.

		September 30, 2017				September 30, 2016
	Level	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
		(In thousands)
Financial assets
Cash and cash equivalents	1	$	313,070	$	313,070	$	450,368	$	450,368
Available-for-sale securities:
Equity securities	1	522		522		101,824		101,824
U.S. government and agency securities	2	211,077		211,077		259,351		259,351
Municipal bonds	2	26,624		26,624		27,670		27,670
Corporate debt securities	2	185,298		185,298		461,138		461,138
Mortgage-backed securities
Agency pass-through certificates	2	834,297		834,297		993,041		993,041
Commercial MBS	2	8,391		8,391		79,870		79,870
Total available-for-sale securities		1,266,209		1,266,209		1,922,894		1,922,894
Held-to-maturity securities:
Mortgage-backed securities
Agency pass-through certificates	2	1,646,856		1,635,913		1,417,599		1,441,556
Total held-to-maturity securities		1,646,856		1,635,913		1,417,599		1,441,556
Loans receivable	3	10,882,622		11,247,586		9,910,920		10,414,794
FDIC indemnification asset	3	8,968		8,564		12,769		12,095
FHLB and FRB stock	2	122,990		122,990		117,205		117,205
Other assets - interest rate contracts	2	1,139		1,139		20,895		20,895
Financial liabilities
Customer accounts	2	10,835,008		10,411,686		10,600,852		10,184,321
FHLB advances and other borrowings	2	2,225,000		2,266,791		2,080,000		2,184,671
Other liabilities - interest rate contracts	2	1,139		1,139		20,895		20,895
Other liabilities - commercial loan hedges	2	174		174		3,312		3,312
Other liabilities - long term borrowing hedges	2	1,693		1,693		31,347		31,347

The following table presents the fair value and balance sheet classification of derivatives outstanding.

	Asset Derivatives						Liability Derivatives
	September 30, 2017			September 30, 2016			September 30, 2017			September 30, 2016
(In thousands)	Balance Sheet	Fair Value		Balance Sheet	Fair Value		Balance Sheet	Fair Value		Balance Sheet	Fair Value
Interest rate contracts	Other assets	$	1,139	Other assets	$	20,895	Other liabilities	$	1,139	Other liabilities	$	20,895
Commercial loan hedges	Other assets	—		Other assets	—		Other liabilities	174		Other liabilities	3,312
Long term borrowing hedges	Other assets	—		Other assets	—		Other liabilities	1,693		Other liabilities	31,347
		$	1,139		$	20,895		$	3,006		$	55,554