Derivatives and Hedging Activities (Tables)

9 Months Ended

Jun. 30, 2017

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.

		June 30, 2017				September 30, 2016
	Level in Fair Value Hierarchy	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
		(In thousands)
Financial assets
Cash and cash equivalents	1	$	359,252	$	359,252	$	450,368	$	450,368
Available-for-sale securities
Equity securities	1	522		522		101,824		101,824
U.S. government and agency securities	2	222,245		222,245		259,351		259,351
Municipal bonds	2	26,736		26,736		27,670		27,670
Corporate debt securities	2	211,209		211,209		461,138		461,138
Mortgage-backed securities
Agency pass-through certificates	2	801,393		801,393		993,041		993,041
Commercial MBS	2	8,309		8,309		79,870		79,870
Total available-for-sale securities		1,270,414		1,270,414		1,922,894		1,922,894
Held-to-maturity securities
Mortgage-backed securities
Agency pass-through certificates	2	1,651,528		1,630,745		1,417,599		1,441,556
Total held-to-maturity securities		1,651,528		1,630,745		1,417,599		1,441,556
Loans receivable	3	10,654,425		11,046,152		9,910,920		10,414,794
FDIC indemnification asset	3	8,745		9,160		12,769		12,095
FHLB and FRB stock	2	124,990		124,990		117,205		117,205
Other assets - interest rate contracts	2	1,342		1,342		20,895		20,895
Financial liabilities
Customer accounts	2	10,634,278		10,208,813		10,600,852		10,184,321
FHLB advances	2	2,275,000		2,319,974		2,080,000		2,184,671
Other liabilities - interest rate contracts	2	1,342		1,342		20,895		20,895
Other liabilities - commercial loan hedges	2	154		154		3,312		3,312
Other liabilities - borrowings hedges	2	2,536		2,536		31,347		31,347

The following table presents the fair value and balance sheet classification of derivatives at June 30, 2017 and September 30, 2016:

	Asset Derivatives						Liability Derivatives
	June 30, 2017			September 30, 2016			June 30, 2017			September 30, 2016
	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	$	1,342	Other assets	$	20,895	Other liabilities	$	1,342	Other liabilities	$	20,895
Commercial loan hedges	Other assets	—		Other assets	—		Other liabilities	154		Other liabilities	3,312
Borrowings hedges	Other assets	—		Other assets	—		Other liabilities	2,536		Other liabilities	31,347
		$	1,342		$	20,895		$	4,032		$	55,554