Sterling Bancorp (STL) 10-Q 9 May 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Mar. 31, 2014	7-May-14
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'STERLING BANCORP	'
Entity Central Index Key	'0001070154	'
Current Fiscal Year End Date	'--09-30	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	83,594,862

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
ASSETS	'	'
Cash and due from banks	$164,645	$113,090
Securities:	'	'
Available for sale	1,233,310	954,393
Held to maturity, at amortized cost (fair value of $527,121 and $250,896 at March 31, 2014 and September 30, 2013, respectively)	527,265	253,999
Total securities	1,760,575	1,208,392
Loans held for sale	21,348	1,011
Gross loans	4,244,354	2,412,898
Allowance for loan losses	-32,015	-28,877
Total loans, net	4,212,339	2,384,021
Federal Home Loan Bank (“FHLB”) and Federal Reserve Bank Stock, at cost	53,346	24,312
Accrued interest receivable	18,154	11,698
Premises and equipment, net	49,041	36,520
Goodwill	387,286	163,117
Core deposit and other intangible assets	50,441	5,891
Bank owned life insurance	117,572	60,914
Other real estate owned	9,275	6,022
Other assets	80,397	34,184
Total assets	6,924,419	4,049,172
LIABILITIES	'	'
Deposits	5,211,724	2,962,294
FHLB and other borrowings	489,801	442,602
FHLB borrowings	19,991	20,351
Senior Notes	98,215	98,033
Subordinated debentures	26,509	0
Mortgage escrow funds	8,711	12,646
Other liabilities	133,002	30,380
Total liabilities	5,987,953	3,566,306
STOCKHOLDERS' EQUITY	'	'
Preferred stock (par value $0.01 per share; 10,000,000 shares authorized; none issued or outstanding)	0	0
Common stock (par value $0.01 per share; 190,000,000 shares authorized; 83,544,307 and 44,351,046 shares outstanding at March 31, 2014 and September 30, 2013, respectively)	912	522
Additional paid-in capital	859,019	403,816
Unallocated common stock held by employee stock ownership plan (“ESOP”)	0	-5,493
Treasury stock, at cost (7,701,717 and 7,837,010 shares at March 31, 2014 and September 30, 2013, respectively)	-87,336	-88,538
Retained earnings	178,156	187,889
Accumulated other comprehensive loss, net of taxes	-14,285	-15,330
Total stockholders’ equity	936,466	482,866
Total liabilities and stockholders’ equity	$6,924,419	$4,049,172

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, except Share data, unless otherwise specified
Securities held-to-maturity at fair value	$527,121	$250,896
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	190,000,000	190,000,000
Common stock, shares outstanding	83,544,307	44,351,046
Treasury stock, shares	7,701,717	7,837,010

Consolidated_Statements_of_Inc

Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Interest and dividend income:	'	'	'	'
Loans	$50,312	$26,378	$93,600	$53,449
Taxable securities	7,573	4,288	14,475	8,572
Non-taxable securities	2,674	1,490	4,835	2,947
Other earning assets	766	264	1,125	597
Total interest and dividend income	61,325	32,420	114,035	65,565
Interest expense:	'	'	'	'
Deposits	2,394	1,624	4,135	3,721
Borrowings	4,903	2,977	9,997	6,102
Total interest expense	7,297	4,601	14,132	9,823
Net interest income	54,028	27,819	99,903	55,742
Provision for loan losses	4,800	2,600	7,800	5,550
Net interest income after provision for loan losses	49,228	25,219	92,103	50,192
Non-interest income:	'	'	'	'
Accounts receivable / factoring commissions and other related fees	3,500	0	5,720	0
Mortgage bank income	2,383	507	3,999	1,253
Deposit fees and service charges	3,904	2,736	7,846	5,514
Net gain (loss) on sale of securities	60	2,229	-585	3,645
Bank owned life insurance	729	491	1,469	1,000
Investment management fees	542	422	1,083	1,127
Other	1,297	467	2,032	1,972
Total non-interest income	12,415	6,852	21,564	14,511
Non-interest expense:	'	'	'	'
Compensation and employee benefits	25,263	11,805	48,819	24,104
Stock-based compensation	927	679	1,918	1,179
Merger-related expenses	388	542	9,456	542
Occupancy and office operations	7,254	3,954	13,587	7,764
Amortization of Intangible Assets	2,511	388	4,386	649
Other real estate owned	61	915	429	1,200
FDIC insurance and regulatory assessments	1,567	753	2,731	1,471
Business Combination, Integration Related Costs	678	0	22,422	0
Other	8,074	4,303	15,951	8,976
Total non-interest expense	46,723	23,339	119,699	45,885
Income before income tax expense	14,920	8,732	-6,032	18,818
Income tax expense	4,588	2,203	-2,361	5,269
Net income	$10,332	$6,529	($3,671)	$13,549
Weighted average common shares:	'	'	'	'
Weighted average common shares basic (shares)	83,497,765	43,743,640	76,924,082	43,704,163
Weighted average common shares diluted (shares)	83,794,107	43,848,486	76,924,082	43,790,915
Per common share	'	'	'	'
Per common share basic (USD per share)	$0.12	$0.15	($0.05)	$0.31
Per common share diluted (USD per share)	$0.12	$0.15	($0.05)	$0.31

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Net income	$10,332	$6,529	($3,671)	$13,549
Other comprehensive (loss) income:	'	'	'	'
Unrealized holding gains (losses) on securities available for sale net of related income tax expense (benefit) of $4,452, ($1,885) and $7, ($3,039)	6,023	-2,753	10	-4,446
Less:	'	'	'	'
Reclassification adjustment for realized gains (losses) included in net income, net of related income tax expense (benefit) of $26, $905 and ($249), $1,480	-34	-1,324	336	-2,165
Reclassification adjustment for other than temporary impaired losses included in net income, net of related income tax benefit of $0, $3 and $0, $13	0	-4	0	-19
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	5,989	-4,073	346	-6,592
Acceleration of future amortization of accumulated other comprehensive (gain) loss on defined benefit pension plan and change in funded status of defined benefit plans, net of related income tax (expense) benefit of ($553), $224 and $517, $419	748	-327	-699	-612
Other comprehensive income (loss)	5,241	-3,746	1,045	-5,980
Total comprehensive income (loss)	$15,573	$2,783	($2,626)	$7,569

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Unrealized holding gains (losses) on securities available for sale, related tax expense (benefit)	$4,452	($1,885)	$7	($3,039)
Reclassification adjustment for net unrealized gains included in net income, related tax expense	26	905	-249	1,480
Reclassification adjustment for other than temporary impaired losses included in net income, related income tax expense	0	-3	0	13
Change in funded status of defined benefit plans, related tax expense	$553	($224)	($517)	($419)

Consolidated_Statement_of_Chan

Consolidated Statement of Changes In Stockholders' Equity (Unaudited) (USD $)	Total	Common stock	Additional paid-in capital	Employee Stock Option [Member]	Unallocated ESOP shares	Treasury stock	Retained earnings	Accumulated other comprehensive income
In Thousands, except Share data, unless otherwise specified
Balance at October 1, 2013 at Sep. 30, 2013	$482,866	'	'	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'	'	'	'
Net income	-3,671	'	'	'	'	'	-3,671	0
Other Comprehensive Income (Loss), Net of Tax	1,045	'	'	'	'	'	'	1,045
Stock Issued During Period, Shares, Acquisitions	39,057,968	'	'	'	'	'	'	'
Stock Issued During Period, Value, Acquisitions	'	390	'	'	'	'	'	'
Business Combination, Consideration Transferred	457,759	'	457,369	'	'	'	'	'
Deferred Compensation Equity	'	0	'	'	0	0	0	0
Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition	45	'	45	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Period Increase (Decrease)	203,964	'	'	'	'	'	'	'
Stock option transactions, net	-2,521	0	-462	'	0	-2,268	-209	0
Stock Issued During Period, Shares, Employee Stock Purchase Plans	-505,717	'	'	'	'	'	'	'
ESOP shares allocated and ESOP termination	-790	0	-1,280	'	-5,493	-5,983	0	0
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	437,046	'	'	'	'	'	'	'
Stock Issued During Period, Value, Restricted Stock Award, Forfeitures	964	0	3,953	'	0	4,917	0	0
Dividends, Cash	5,853	0	0	'	0	0	5,853	0
Balance at Mar. 31, 2014	$936,466	$912	$859,019	$0	'	($87,336)	$178,156	($14,285)
Balance, shares at Mar. 31, 2014	83,544,307	'	'	'	'	'	'	'

Consolidated_Statement_of_Chan1

Consolidated Statement of Changes In Stockholders' Equity (Parenthetical) (Unaudited)	6 Months Ended
	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]	'
ESOP shares allocated or committed to be released for allocation, shares	505,717

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:	'	'
Net income	$3,671,000	($13,549,000)
Adjustments to reconcile net income to net cash provided by operating activities	'	'
Provision for loan losses	7,800,000	5,550,000
Loss on real estate owned	176,000	34,000
Depreciation of premises and equipment	3,419,000	2,342,000
Asset Impairment Charges	9,302,000	0
Amortization of intangibles	4,386,000	649,000
Net gain on loans held for sale	-3,999,000	-1,253,000
Net gain on sale of securities	585,000	-3,645,000
Net gain on sale of premises and equipment	-93,000	-5,000
Net amortization of premium on securities	1,588,000	1,768,000
(Amortization) accretion on borrowings	87,000	-192,000
Accretion of early extinguishment fees on borrowings	851,000	733,000
ESOP and RRP expense	1,464,000	832,000
Stock option compensation expense	454,000	347,000
Originations of loans held for sale	-247,971,000	-48,642,000
Proceeds from sales of loans held for sale	241,966,000	56,360,000
Increase in cash surrender value of bank owned life insurance	-1,284,000	-899,000
Other adjustments (principally net changes in other assets and other liabilities)	19,183,000	-24,424,000
Net cash (used in) provided by operating activities	34,243,000	3,104,000
Cash flows from investing activities:	'	'
Purchases of available for sale securities	-219,145,000	-209,010,000
Purchases of held to maturity securities	-100,841,000	-81,838,000
Proceeds from maturities, calls and other principal payments on securities:	'	'
Available for sale	66,423,000	128,589,000
Held to maturity	11,242,000	39,003,000
Proceeds from Sale of Available-for-sale Securities	305,489,000	136,804,000
Proceeds from Sale of Held-to-maturity Securities	0	1,234,000
Payments for Loan originations	793,038,000	495,649,000
Payments for (Proceeds from) Loans and Leases	-662,828,000	-402,295,000
Proceeds from sales of other real estate owned	3,478,000	2,085,000
Sale (purchase) of FHLB stock, net	4,519,000	-1,002,000
Payments to Acquire Federal Reserve Bank Stock	-25,873,000	0
Purchases of premises and equipment	-1,648,000	-1,471,000
Net cash used in investing activities	191,232,000	-78,960,000
Cash flows from financing activities:	'	'
Net Change Interest and Noninterest-bearing Deposits, Domestic	118,160,000	-271,387,000
Net (decrease) increase in time deposits	-165,920,000	-40,106,000
Net increase in short-term borrowings	-103,540,000	32,385,000
Repayments of Long-term Debt	62,460,000	10,126,000
Proceeds from Issuance of Long-term Debt	49,887,000	0
Net increase in mortgage escrow funds	-3,935,000	5,663,000
Proceeds from Stock Options Exercised	2,357,000	148,000
Other stock-based compensation transactions	45,000	13,000
Cash dividends paid	-8,514,000	-5,320,000
Net cash used in financing activities	-173,920,000	-288,730,000
Net decrease in cash and cash equivalents	51,555,000	-364,586,000
Cash and cash equivalents at beginning of period	113,090,000	437,982,000
Cash and cash equivalents at end of period	164,645,000	73,396,000
Supplemental information:	'	'
Interest payments	14,733,000	10,096,000
Income tax payments	8,670,000	4,603,000
Real Estate Acquired in Settlement of Loans	1,092,000	1,983,000
Settlements, Security Purchases, Subsequent Periods	2,213,000	4,823,000
Securities held to maturity transferred to available for sale	165,230,000	0
Securities available for sale transferred to held to maturity	221,904,000	0
Non-cash assets acquired:	'	'
Securities available for sale	233,190,000	0
Noncash Or Part Noncash Acquisition held to maturity securities Acquired	374,721,000	0
Noncash or part Noncash Acquisition Loan held for sale acquired	30,341,000	0
Total loans, net	1,698,108,000	0
Federal Reserve Bank stock	7,680,000	0
Accrued interest receivable	6,590,000	0
Goodwill	224,169,000	0
Core deposit intangible	20,089,000	0
Noncash or Part Noncash Acquisition, Trade Name Acquired	20,500,000	0
Noncash or Part Noncash Acquisition, BOLI Acquired	55,374,000	0
Premises and equipment, net	23,594,000	0
Noncash or Part Noncash Acquisition, Other Real Estate Owned	5,815,000	0
Other assets	22,551,000	0
Total non-cash assets acquired	2,722,722,000	0
Liabilities assumed:	'	'
Deposits	2,297,190,000	0
FHLB borrowings	100,619,000	0
Noncash or Part Noncash Acquisition, other borrowings	62,465,000	0
Noncash or Part Noncash Acquisition, Net Subordinated Debentures	26,527,000	0
Other liabilities	55,960,000	0
Total liabilities assumed	2,542,761,000	0
Net non-cash assets acquired	179,961,000	0
Cash Acquired from Acquisition	277,798,000	0
Cash and cash equivalents acquired	$457,759,000	$0

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	Legacy Sterling Bancorp Merger Transaction
	On October 31, 2013, Provident New York Bancorp completed its merger with Sterling Bancorp (“legacy Sterling”). In connection with the merger, Provident New York Bancorp completed the following corporate actions:
	•	Legacy Sterling merged with and into Provident New York Bancorp. Provident New York Bancorp was the accounting acquirer and the surviving entity;
	•	Provident New York Bancorp changed its legal entity name to Sterling Bancorp and became a bank holding company and a financial holding company as defined by the Bank Holding Company Act of 1956, as amended;
	•	Provident Bank converted to a national bank charter;
	•	Sterling National Bank merged into Provident Bank;
	•	Provident Bank changed its legal entity name to Sterling National Bank; and
	•	Provident Municipal Bank merged into Sterling National Bank.
	We refer to the transactions detailed above collectively as the “Merger”.
	Legacy Sterling results since November 1, 2013 are included in the results from operations in this Report on Form 10-Q; therefore, the results included in this Report on Form 10-Q for the six months ended March 31, 2014 include five months of operations of legacy Sterling and six months of operations of the Company.
	The consolidated financial statements include the accounts of Sterling Bancorp (“Sterling”, the “Company” or when necessary “legacy Provident”), PBNY Holdings, Inc. which has an investment in PB Madison Title Agency L.P., a company that provides title searches and title insurance for residential and commercial real estate, LandSave Development, LLC, an inactive subsidiary, Provident Risk Management (a captive insurance company), Sterling National Bank (the “Bank”) and the Bank’s wholly owned subsidiaries. These subsidiaries included at March 31, 2014 (i) Provident REIT, Inc., WSB Funding, Inc. and Sterling Real Estate Holding Company, Inc., which are real estate investment trusts that hold a portion of the Company’s real estate loans; (ii) Provest Services Corp. I, which has invested in a low-income housing partnership; (iii) Provest Services Corp. II, which has engaged a third-party provider to sell mutual funds and annuities to the Bank’s customers; and (iv) companies that hold other real estate owned by the Bank. Intercompany transactions and balances are eliminated in consolidation.
	The consolidated financial statements have been prepared by management and, in the opinion of management, include all adjustments, consisting of normal recurring accruals, necessary for a fair presentation of the Company’s financial position and results of its operations as of the dates and for the periods presented. Although certain information and footnote disclosures have been condensed or omitted pursuant to the rules and regulations of the United States Securities and Exchange Commission applicable to quarterly reports on Form 10-Q, the Company believes that the disclosures are adequate to make the information presented clear. The results of operations for the six months ended March 31, 2014 are not necessarily indicative of results to be expected for other interim periods or the entire fiscal year ending September 30, 2014. The unaudited consolidated financial statements presented herein should be read in conjunction with the annual audited financial statements included in the Company’s Form10-K for the fiscal year ended September 30, 2013.
	The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets, liabilities, income and expense. Actual results could differ significantly from these estimates. A material estimate that is particularly susceptible to near-term change is the allowance for loan losses, which reflects the application of a critical accounting policy (see Note 4. Loans).

Acquisition

Acquisition	6 Months Ended
	Mar. 31, 2014
Acquisition [Abstract]	'
Business Combination Disclosure [Text Block]	'
	Acquisition
	On October 31, 2013, the Company completed the Merger. Under the terms of the Merger agreement, legacy Sterling shareholders received 1.2625 shares of the Company’s common stock for each share of legacy Sterling common stock, which resulted in the issuance of 39,057,968 shares. Based on the closing stock price of $11.72 per share on October 31, 2013, the aggregate consideration paid to legacy Sterling shareholders was $457,759. Consistent with the Company’s strategy, the primary reason for the Merger was the expansion of the Company’s geographic footprint in the greater New York metropolitan region and beyond.
	The assets acquired and liabilities assumed were accounted for under the acquisition method of accounting. The assets and liabilities, both tangible and intangible, were recorded at their fair values as of October 31, 2013 based on management’s best estimate using the information available as of the Merger date. The application of the acquisition method of accounting resulted in the recognition of goodwill of $224,169, a core deposit intangible of $20,089 and a trade name intangible of $20,500.  As of October 31, 2013, legacy Sterling had assets with a book value of approximately $2,759,628, loans including loans held for sale with a book value of approximately $1,735,142, and deposits with a book value of approximately $2,296,713. The table below summarizes the amounts recognized as of the Merger date for each major class of assets acquired and liabilities assumed, the estimated fair value adjustments and the amounts recorded in the Company’s financial statements at fair value at the Merger date:
	Consideration paid through Sterling Bancorp common stock issued to legacy Sterling shareholders				$	457,759
		Legacy Sterling carrying value				Fair value adjustments				As recorded at acquisition
	Cash and cash equivalents	$	277,798			$	—			$	277,798
	Investment securities	613,154				(5,243		)	(a)	607,911
	Loans held for sale	30,341				—				30,341
	Loans	1,704,801				(6,693		)	(b)	1,698,108
	Federal Reserve Bank stock	7,680				—				7,680
	Bank owned life insurance	55,374				—				55,374
	Premises and equipment	21,293				2,301			(c)	23,594
	Accrued interest receivable	6,590				—				6,590
	Core deposit and other intangibles	—				20,089			(d)	20,089
	Trade name intangible	—				20,500			(e)	20,500
	Other real estate owned	1,720				4,095			(f)	5,815
	Other assets	40,877				(18,326		)	(g)	22,551
	Deposits	(2,296,713		)		(477		)	(h)	(2,297,190		)
	FHLB borrowings	(100,346		)		(273		)	(i)	(100,619		)
	Other borrowings	(62,465		)		—				(62,465		)
	Subordinated debentures	(25,774		)		(753		)	(j)	(26,527		)
	Other liabilities	(60,462		)		4,502			(k)	(55,960		)
	Total identifiable net assets	$	213,868			$	19,722			$	233,590
	Goodwill recorded in the Merger									224,169
	Goodwill at September 30, 2013									163,117
	Goodwill at March 31, 2014									$	387,286
	Explanation of certain fair value related adjustments:
	(a)	Represents the fair value adjustment on investment securities held to maturity.
	(b)	Represents the elimination of legacy Sterling’s allowance for loan losses and an adjustment of the amortized cost of loans to estimated fair value, which includes an interest rate mark and credit mark.
	(c)	Represents an adjustment to reflect the fair value of leasehold improvements.
	(d)	Represents intangible assets recorded to reflect the fair value of core deposits and below market rent on leased premises. The core deposit asset was recorded as an identifiable intangible asset and will be amortized on an accelerated basis over the estimated average life of the deposit base. The below market rent intangible asset will be amortized on a straight-line basis over the remaining term of the leases.
	(e)	Represents the estimated fair value of Sterling Bancorp’s trade name. This intangible asset will not be amortized and will be reviewed at least annually for impairment.
	(f)	Represents an adjustment to an acquired property which legacy Sterling utilized as a financial center and recorded as premises and equipment. As the Company intends to sell this asset, it was recorded in other real estate owned at estimated fair value determined using an independent appraisal.
	(g)	Consists primarily of adjustments in net deferred tax assets resulting from the fair value adjustments related to the acquired assets, liabilities assumed and identifiable intangibles recorded.
	(h)	Represents the fair value adjustment on deposits as the weighted average interest rate of deposits assumed exceeded the cost of similar funding available in the market at the time of the Merger.
	(i)	Represents the fair value adjustment on FHLB borrowings as the weighted average interest rate of FHLB borrowings assumed exceeded the cost of similar funding available in the market at the time of the Merger.
	(j)	Represents the fair value adjustment on subordinated debentures as the weighted average interest rate of the debentures assumed exceeded the cost of similar debt funding available in the market at the time of the Merger.
	(k)	Represents the fair value of other liabilities assumed at the Merger date.
	Except for collateral dependent loans with deteriorated credit quality, the fair values for loans acquired from legacy Sterling were estimated using cash flow projections based on the remaining maturity and repricing terms. Cash flows were adjusted by estimating future credit losses and the rate of prepayments. Projected monthly cash flows were then discounted to present value using a risk-adjusted market rate for similar loans. For collateral dependent loans with deteriorated credit quality, fair value was estimated by analyzing the value of the underlying collateral, assuming the fair values of the loans were derived from the eventual sale of the collateral. These values were discounted using market derived rates of return, with consideration given to the period of time and costs associated with the foreclosure and disposition of the collateral. There was no carryover of legacy Sterling’s allowance for loan losses associated with the loans that were acquired, as the loans were initially recorded at fair value on the date of the Merger.
	The acquired loan portfolio subject to purchased credit impairment accounting guidance (ASC 310-30) as of October 31, 2013 was comprised of collateral dependent loans with deteriorated credit quality as follows:
		ASC 310-30 loans
	Contractual principal balance at acquisition	$	24,176
	Principal not expected to be collected (non-accretable discount)	(10,927		)
	Expected cash flows at acquisition	13,249
	Interest component of expected cash flows (accretable discount)	—
	Fair value of acquired loans	$	13,249
	The core deposit intangible asset recognized is being amortized over its estimated useful life of approximately 10 years utilizing the accelerated method. Other intangibles consist of below market rents which are amortized over the remaining life of each lease using the straight-line method.
	Goodwill is not amortized for book purposes; however, it is reviewed at least annually for impairment and is not deductible for tax purposes.
	The fair value of premises and equipment and other real estate owned was estimated using appraisals of like kind properties and assets. Premises, equipment and leasehold improvements will be amortized or depreciated over their estimated useful lives ranging from one to five years for equipment or over the life of the lease for leasehold improvements. Other real estate owned is not amortized and is carried at estimated fair value determined by the appraised value less costs to sell.
	The fair value of retail demand and interest bearing deposit accounts was assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. The fair value of time deposits was estimated by discounting the contractual future cash flows using market rates offered for time deposits of similar remaining maturities. The fair value of borrowed funds was estimated by discounting the future cash flows using market rates for similar borrowings.
	Direct acquisition and integration costs of the Merger were expensed as incurred and totaled $388 and $9,456 and $542 and $542 for the three and six months ended March 31, 2014 and 2013, respectively. These items were recorded as Merger-related expenses on the statement of operations. Other direct integration costs of the Merger for the three and six months ended March 31, 2014 included a charge for asset write-downs, employee retention and severance compensation which totaled $22,422. These items were recorded in non-interest expense in the statement of operations.
	The following table presents selected unaudited pro forma financial information reflecting the Merger assuming it was completed as of October 1, 2012. The unaudited pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the Merger actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full fiscal year period. Pro forma basic and diluted earnings per common share were calculated using the Company’s actual weighted average shares outstanding for the periods presented, plus the incremental shares issued, assuming the Merger occurred at the beginning of the periods presented. The unaudited pro forma information is based on the actual financial statements of the Company for the periods presented, and on the actual financial statements of legacy Sterling for the 2012 period presented and in 2013 until the date of the Merger, at which time legacy Sterling’s results of operations were included in the Company’s financial statements.
	The unaudited pro forma information, for the six months ended March 31, 2014 and 2013, set forth below reflects adjustments related to (a) purchase accounting fair value adjustments; (b) amortization of core deposit and other intangibles; and (c) adjustments to interest income and expense due to amortization of premiums and accretion of discounts. Direct Merger-related expenses and charges incurred in the three and six months ended March 31, 2014 to write-down assets and accrue for retention and severance compensation are assumed to have occurred prior to October 1, 2012. Furthermore, the unaudited pro forma information does not reflect management’s estimate of any revenue enhancement opportunities or anticipated potential cost savings.
		Pro forma for the
		six months ended March 31,
		2014				2013
	Net interest income	$	100,571			$	90,586
	Non-interest income	28,590				34,232
	Non-interest expense	99,368				97,026
	Net income	20,110				19,970
	Pro forma earnings per share:
	Basic	$	0.24			$	0.24
	Diluted	0.24				0.24

Securities

Securities	6 Months Ended
	Mar. 31, 2014
Marketable Securities [Abstract]	'
Securities	'
	Securities
	A summary of the amortized cost and estimated fair value of our securities is presented below:
		31-Mar-14												30-Sep-13
		Amortized			Gross			Gross			Fair value			Amortized		Gross			Gross			Fair value
		cost			unrealized			unrealized						cost		unrealized			unrealized
					gains			losses								gains			losses
	Available for Sale
	Residential mortgage-backed securities (“MBS”):
	Agency-backed	$	458,121		$	1,925		$	(2,531	)	$	457,515		$	284,837	$	1,849		$	(4,157	)	$	282,529
	CMO/Other MBS	136,304			235			(1,688		)	134,851			169,336		356			(3,038		)	166,654
	Total residential MBS	594,425			2,160			(4,219		)	592,366			454,173		2,205			(7,195		)	449,183
	Other securities:
	Federal agencies	217,942			3			(8,244		)	209,701			273,637		—			(12,090		)	261,547
	Corporate	225,628			180			(3,610		)	222,198			118,575		153			(3,795		)	114,933
	State and municipal	134,881			3,038			(783		)	137,136			127,324		3,447			(2,041		)	128,730
	Trust preferred	65,277			1,809			—			67,086			—		—			—			—
	Mutual funds	4,874			—			(51		)	4,823			—		—			—			—
	Total other securities	648,602			5,030			(12,688		)	640,944			519,536		3,600			(17,926		)	505,210
	Total available for sale	$	1,243,027		$	7,190		$	(16,907	)	$	1,233,310		$	973,709	$	5,805		$	(25,121	)	$	954,393
		31-Mar-14												30-Sep-13
		Amortized			Gross			Gross			Fair value			Amortized		Gross			Gross			Fair value
		cost			unrecognized			unrecognized						cost		unrecognized			unrecognized
					gains			losses								gains			losses
	Held to Maturity
	Residential MBS:
	Agency-backed	$	128,212		$	691		$	(362	)	$	128,541		$	130,371	$	716		$	(108	)	$	130,979
	CMO/Other MBS	67,982			13			(1,859		)	66,136			25,776		33			(315		)	25,494
	Total residential MBS	196,194			704			(2,221		)	194,677			156,147		749			(423		)	156,473
	Other securities:
	Federal agencies	135,998			740			(1,375		)	135,363			77,341		—			(3,458		)	73,883
	State and municipal	193,573			2,300			(312		)	195,561			19,011		556			(546		)	19,021
	Other	1,500			20			—			1,520			1,500		19			—			1,519
	Total other securities	331,071			3,060			(1,687		)	332,444			97,852		575			(4,004		)	94,423
	Total held to maturity	$	527,265		$	3,764		$	(3,908	)	$	527,121		$	253,999	$	1,324		$	(4,427	)	$	250,896
	In accordance with ASC Subtopic 320-10-25-6, in a significant business combination a company may transfer held to maturity securities to available for sale securities to maintain the company’s existing interest rate risk position or credit risk policy. Based on management’s review of the combined investment securities portfolio and implications for asset and liability management, investment securities totaling $165,230 were transferred from held to maturity to available for sale. Investment securities that were transferred included residential mortgage-backed securities, federal agency securities and state and municipal securities and was based mainly on the premium amortization and extension risk inherent in these securities. Concurrent with this repositioning, a total of $221,904 of investment securities were also transferred from available for sale to held to maturity. Substantially all of the securities transferred from available for sale to held to maturity have a maturity date in 2020 or beyond. At the date of transfer, these securities were in an unrealized loss position of $9,657, which will be accreted into interest income using the level yield method over the life of the securities, which is estimated to be approximately 5.75 years, and at March 31, 2014 the unrealized loss accreted to $9,528. The unrealized loss amount is included in accumulated other comprehensive (loss) on an after-tax basis. Management believes the transfers of investment securities highlighted above maintain the Company’s interest rate risk position and credit risk profile on a combined basis post-Merger.
	The amortized cost and estimated fair values of securities at March 31, 2014 are presented below by contractual maturity. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Residential mortgage-backed securities are shown separately since they are not due at a single maturity date.
		March 31, 2014
		Available for sale						Held to maturity
		Amortized			Fair			Amortized			Fair
		cost			value			cost			value
	Remaining period to contractual maturity:
	One year or less	$	27,970		$	27,977		$	8,790		$	8,874
	One to five years	180,125			179,888			5,110			5,356
	Five to ten years	367,390			358,028			149,874			149,293
	Greater than ten years	73,117			75,051			167,297			168,921
	Total other securities	648,602			640,944			331,071			332,444
	Residential MBS	594,425			592,366			196,194			194,677
	Total securities	$	1,243,027		$	1,233,310		$	527,265		$	527,121
	Sales of securities for the three and six months ended March 31, 2014 and 2013 were as follows:
		For the three months ended March 31,						For the six months ended March 31,
		2014			2013			2014			2013
	Available for sale securities:
	Proceeds from sales	$	55,778		$	94,839		$	305,489		$	136,804
	Gross realized gains	65			2,202			276			3,618
	Gross realized losses	(5		)	(10		)	(861		)	(10		)
	Income tax (expense) benefit on realized gains (losses)	(18		)	(552		)	229			(1,010		)
	Held to maturity securities:
	Proceeds from sales	—			1,234			—			1,234
	Gross realized gains	—			37			—			37
	Income tax expense on realized gains	—			(9		)	—			(10		)
	The following table summarizes securities with unrealized losses, segregated by the length of time in a continuous unrealized loss position:
		Continuous unrealized loss position
		Less than 12 Months						12 months or longer						Total
	Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
	value			losses			value			losses			value		losses
Available for Sale
31-Mar-14
Residential MBS:
Agency-backed	$	179,009		$	(691	)	$	67,082		$	(1,840	)	$	246,091	$	(2,531	)
CMO/Other MBS	64,069			(676		)	27,175			(1,012		)	91,244		(1,688		)
Total residential MBS	243,078			(1,367		)	94,257			(2,852		)	337,335		(4,219		)
Federal agencies	51,116			(2,048		)	158,091			(6,196		)	209,207		(8,244		)
Corporate	86,663			(925		)	90,763			(2,685		)	177,426		(3,610		)
State and municipal	28,293			(252		)	16,308			(531		)	44,601		(783		)
Mutual fund	4,827			(51		)	—			—			4,827		(51		)
Total	$	413,977		$	(4,643	)	$	359,419		$	(12,264	)	$	773,396	$	(16,907	)
30-Sep-13
Residential MBS:
Agency-backed	$	137,265		$	(4,157	)	$	—		$	—		$	137,265	$	(4,157	)
CMO/Other MBS	122,324			(2,742		)	7,820			(296		)	130,144		(3,038		)
Total residential MBS	259,589			(6,899		)	7,820			(296		)	267,409		(7,195		)
Federal agencies	261,547			(12,090		)	—			—			261,547		(12,090		)
Corporate	95,013			(3,795		)	—			—			95,013		(3,795		)
State and municipal	43,585			(2,033		)	112			(8		)	43,697		(2,041		)
Total	$	659,734		$	(24,817	)	$	7,932		$	(304	)	$	667,666	$	(25,121	)
	Continuous unrealized loss position
	Less than 12 Months						12 Months or longer						Total
	Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
	value			losses			value			losses			value		losses
Held to Maturity
March 31, 2014
Residential MBS:
Agency-backed	$	61,535		$	(362	)	$	—		$	—		$	61,535	$	(362	)
CMO/Other MBS	61,924			(1,859		)	—			—			61,924		(1,859		)
Total residential MBS	123,459			(2,221		)	—			—			123,459		(2,221		)
Federal agencies	40,085			(1,375		)	—			—			40,085		(1,375		)
State and municipal	29,723			(1,312		)	—			—			29,723		(312		)
Total	$	193,267		$	(3,908	)	$	—		$	—		$	193,267	$	(3,908	)
30-Sep-13
Residential MBS:
Agency-backed	$	10,963		$	(86	)	$	—		$	—		$	10,963	$	(86	)
CMO/Other MBS	31,412			(337		)	—			—			31,412		(337		)
Total residential MBS	42,375			(423		)	—			—			42,375		(423		)
Federal agencies	73,883			(3,458		)	—			—			73,883		(3,458		)
State and municipal	9,530			(546		)	—			—			9,530		(546		)
Total	$	125,788		$	(4,427	)	$	—		$	—		$	125,788	$	(4,427	)
Substantially all of the unrealized losses at March 31, 2014 relate to investment grade debt securities and are attributable to changes in market interest rates subsequent to purchase. At March 31, 2014, a total of 224 available for sale securities were in a continuous unrealized loss position for less than 12 months and 150 securities were in an unrealized loss position for 12 months or longer. For securities with fixed maturities, there are no securities past due or securities for which the Company currently believes it is not probable that it will collect all amounts due according to the contractual terms of the investment.
Declines in the fair value of available for sale and held to maturity securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in other comprehensive income. In estimating other-than-temporary impairment losses (“OTTI”), management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the intent and ability of the Company to retain the investment for a period of time sufficient to allow for an anticipated recovery in cost.
Securities pledged for borrowings at FHLB and other institutions, and securities pledged for municipal deposits and other purposes were as follows:
	March 31, 2014			September 30, 2013
Available for sale securities pledged for borrowings, at fair value	$	268,017		$	199,642
Available for sale securities pledged for municipal deposits, at fair value	505,185			580,756
Held to maturity securities pledged for back-to-back swaps, at amortized cost	5,037			4,645
Held to maturity securities pledged for borrowings, at amortized cost	71,393			55,497
Held to maturity securities pledged for municipal deposits, at amortized cost	322,666			167,926
Total securities pledged	$	1,172,298		$	1,008,466

Loans

Loans	6 Months Ended
	Mar. 31, 2014
Loans [Abstract]	'
Loans	'
	Loans
	The composition of the Company’s loan portfolio, excluding loans held for sale, was the following:
		March 31, 2014				September 30, 2013
	Commercial:
	Commercial & industrial	$	1,072,203			$	439,787
	Payroll finance	126,830				—
	Warehouse lending	150,280				—
	Factored receivables	145,979				—
	Equipment financing	332,082				—
	Total commercial	1,827,374				439,787
	Commercial mortgage:
	Commercial real estate	1,315,220				969,490
	Multi-family	298,782				307,547
	Acquisition, development & construction	90,905				102,494
	Total commercial mortgage	1,704,907				1,379,531
	Total commercial and commercial mortgage	3,532,281				1,819,318
	Residential mortgage	512,875				400,009
	Consumer:
	Home equity lines of credit	152,820				156,995
	Other consumer loans	46,378				36,576
	Total consumer	199,198				193,571
	Total loans	4,244,354				2,412,898
	Allowance for loan losses	(32,015		)		(28,877		)
	Total loans, net	$	4,212,339			$	2,384,021
	Total loans include net deferred loan origination costs of $1,109 at March 31, 2014 and $1,201 at September 30, 2013.
	Loans acquired from legacy Sterling were a total of $1,698,108 comprised of $1,683,454 of loans that were not considered impaired at the acquisition date and $14,654 of loans that were determined to be impaired at the time of acquisition. The impaired loans were accounted for in accordance with ASC Topic 310-30 Accounting for Certain Loans or Debt Securities Acquired in a Transfer (“ASC 310-30”). At March 31, 2014, the net recorded amount of loans accounted for under ASC 310-30 was $11,305.
	Loans acquired in the Merger that were determined to be purchased credit impaired were all considered collateral dependent loans. Therefore, estimated fair value calculations and projected cash flows included only return of principal and no interest income. There was no accretable yield associated with these loans during the three and six months ended March 31, 2014.
	At March 31, 2014, the Company pledged loans totaling $924,115 to the FHLB as collateral for certain borrowing arrangements. See Note 6. FHLB and Other Borrowings.
	The following tables set forth the amounts and status of the Company’s loans and troubled debt restructurings (“TDRs”) at March 31, 2014 and September 30, 2013:
		March 31, 2014
		Current				30-59				60-89			90+			Non-			Total
						days				days			days			accrual
						past due				past due			past due
	Commercial & industrial	$	1,068,821			$	617			$	355		$	7		$	2,403		$	1,072,203
	Payroll finance	84,950				31,324				7,351			3,205			—			126,830
	Warehouse lending	150,280				—				—			—			—			150,280
	Factored receivables	135,834				4,620				2,628			1,905			992			145,979
	Equipment financing	330,559				1,077				170			—			276			332,082
	Commercial real estate	1,289,316				1,389				7,737			—			16,778			1,315,220
	Multi-family	298,782				—				—			—			—			298,782
	Acquisition, development & construction	75,115				272				737			—			14,781			90,905
	Residential mortgage	494,438				2,175				1,063			273			14,926			512,875
	Consumer	192,256				1,289				928			4			4,721			199,198
	Total loans	$	4,120,351			$	42,763			$	20,969		$	5,394		$	54,877		$	4,244,354
	Total TDRs included above	$	14,502			$	1,241			$	2,232		$	—		$	12,116		$	30,091
	Non-performing loans:
	Loans 90+ days past due and still accruing															$	5,394
	Non-accrual loans															54,877
	Total non-performing loans															$	60,271
		September 30, 2013
		Current				30-59				60-89			90+			Non-			Total
						days				days			days			accrual
						past due				past due			past due
	Commercial & industrial	$	438,818			$	178			$	2		$	289		$	500		$	439,787
	Commercial real estate	1,263,933				1,978				2,357			1,574			7,195			1,277,037
	Acquisition, development & construction	96,306				768				—			—			5,420			102,494
	Residential mortgage	390,072				354				267			1,832			7,484			400,009
	Consumer	190,393				566				—			404			2,208			193,571
	Total loans	$	2,379,522			$	3,844			$	2,626		$	4,099		$	22,807		$	2,412,898
	Total TDRs included above	$	23,754			$	—			$	—		$	141		$	2,199		$	26,094
	Non-performing loans:
	Loans 90+ days past due and still accruing															$	4,099
	Non-accrual loans															22,807
Total non-performing loans															$	26,906
Activity in the allowance for loan losses for the three and six months ended March 31, 2014 and 2013 is summarized below:
	For the three months ended March 31, 2014
	Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
	balance											charge-offs
Commercial & industrial	$	6,886			$	(1,164	)		$	74		$	(1,090	)	$	873		$	6,669
Payroll finance	—				—				—			—			610			610
Warehouse lending	—				—				—			—			132			132
Factored receivables	—				(289		)		—			(289		)	668			379
Equipment financing	—				(167		)		—			(167		)	1,473			1,306
Commercial real estate	9,992				(280		)		19			(261		)	1,135			10,866
Acquisition, development & construction	5,857				(1,260		)		—			(1,260		)	(1,038		)	3,559
Residential mortgage	4,600				(148		)		1			(147		)	112			4,565
Consumer	3,277				(204		)		21			(183		)	835			3,929
Total loans	$	30,612			$	(3,512	)		$	115		$	(3,397	)	$	4,800		$	32,015
Annualized net charge-offs to average loans outstanding																		0.34		%
Loans acquired from Gotham Bank and legacy Sterling with a carrying amount of $1,378,608 were not included in the Company’s allowance for loan losses at March 31, 2014 as such loans include a fair value discount that considers expected lifetime credit losses.
	For the three months ended March 31, 2013
	Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
	balance											charge-offs
Commercial & industrial	$	5,533			$	(359	)		$	127		$	(232	)	$	(930	)	$	4,371
Commercial real estate	7,616				(1,199		)		331			(868		)	2,401			9,149
Acquisition, development & construction	7,026				(567		)		164			(403		)	(521		)	6,102
Residential mortgage	4,368				(959		)		9			(950		)	1,025			4,443
Consumer	3,571				(748		)		31			(717		)	625			3,479
Total loans	$	28,114			$	(3,832	)		$	662		$	(3,170	)	$	2,600		$	27,544
Annualized net charge-offs to average loans outstanding																		0.58		%
	For the six months ended March 31, 2014
	Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
	balance											charge-offs
Commercial & industrial	$	5,302			$	(1,692	)		$	575		$	(1,117	)	$	2,484		$	6,669
Payroll finance	—				—				—			—			610			610
Warehouse lending	—				—				—			—			132			132
Factored receivables	—				(289		)		—			(289		)	668			379
Equipment financing	—				(167		)		—			(167		)	1,473			1,306
Commercial real estate	9,967				(951		)		56			(895		)	1,794			10,866
Acquisition, development & construction	5,806				(1,478		)		—			(1,478		)	(769		)	3,559
Residential mortgage	4,474				(418		)		8			(410		)	501			4,565
Consumer	3,328				(351		)		45			(306		)	907			3,929
Total loans	$	28,877			$	(5,346	)		$	684		$	(4,662	)	$	7,800		$	32,015
Annualized net charge-offs to average loans outstanding																		0.25		%
	For the six months ended March 31, 2013
	Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
	balance											charge-offs
Commercial & industrial	$	4,603			$	(518	)		$	247		$	(271	)	$	39		$	4,371
Commercial real estate	7,230				(1,427		)		412			(1,015		)	2,934			9,149
Acquisition, development & construction	8,526				(2,161		)		169			(1,992		)	(432		)	6,102
Residential mortgage	4,359				(1,909		)		60			(1,849		)	1,933			4,443
Consumer	3,564				(1,231		)		70			(1,161		)	1,076			3,479
Total loans	$	28,282			$	(7,246	)		$	958		$	(6,288	)	$	5,550		$	27,544
Annualized net charge-offs to average loans outstanding																		0.58		%
Management considers a loan to be impaired when, based on current information and events, it is determined that the Company will not be able to collect all amounts due according to the loan contract, including scheduled interest payments. Determination of impairment is treated the same across all classes of loans on a loan-by-loan basis, except residential mortgage loans and home equity lines of credit with an outstanding balance of $500 or less which are evaluated for impairment on a homogeneous pool basis. When management identifies a loan as impaired, the impairment is measured based on the present value of expected future cash flows, discounted at the loan’s effective interest rate, except when the sole remaining source of repayment of the loan is the operation or liquidation of the collateral. In these cases, management uses the current fair value of the collateral, less selling costs when foreclosure is probable, instead of discounted cash flows. If management determines that the value of the impaired loan is less than the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount), impairment is generally recognized through a charge-off to the allowance for loan losses.
When the ultimate collectibility of the total principal of an impaired loan is in doubt and the loan is on non-accrual status, all payments are applied to principal, under the cost recovery method. When the ultimate collectibility of the total principal of an impaired loan is not in doubt and the loan is on non-accrual status, contractual interest is credited to interest income when received, under the cash basis method.
The following table sets forth loans evaluated for impairment by segment and the allowance evaluated by segment at March 31, 2014:
	Loans evaluated by segment														Allowance evaluated by segment
	Individually				Collectively				Purchased credit impaired loans			Total			Individually			Collectively			Total allowance for loan losses
	evaluated for				evaluated for							loans			evaluated for			evaluated for
	impairment				impairment										impairment			impairment
Commercial & industrial	$	1,841			$	1,068,031			$	2,331		$	1,072,203		$	—		$	6,669		$	6,669
Payroll finance	—				126,830				—			126,830			—			610			610
Warehouse lending	—				150,280				—			150,280			—			132			132
Factored receivables	992				144,987				—			145,979			—			379			379
Equipment financing	—				332,082				—			332,082			—			1,306			1,306
Commercial real estate	12,732				1,594,397				6,873			1,614,002			—			10,866			10,866
Acquisition, development & construction	21,005				69,900				—			90,905			—			3,559			3,559
Residential mortgage	515				508,932				3,428			512,875			—			4,565			4,565
Consumer	—				199,198				—			199,198			—			3,929			3,929
Total loans	$	37,085			$	4,194,637			$	12,632		$	4,244,354		$	—		$	32,015		$	32,015
There was no amount included in the allowance for loan losses associated with purchased credit impaired loans at March 31, 2014, as there was no further deterioration in the credit quality of these loans since the Merger date.
The following table sets forth the loans evaluated for impairment by segment and the allowance evaluated by segment at September 30, 2013:
	Loans evaluated by segment											Allowance evaluated by segment
	Individually				Collectively				Total			Individually			Collectively			Total allowance for loan losses
	evaluated for				evaluated for				loans			evaluated for			evaluated for
	impairment				impairment							impairment			impairment
Commercial & industrial	$	2,631			$	437,156			$	439,787		$	249		$	5,053		$	5,302
Commercial real estate & multi-family	14,091				1,262,946				1,277,037			803			9,164			9,967
Acquisition, development & construction	19,582				82,912				102,494			540			5,266			5,806
Residential mortgage	515				399,494				400,009			—			4,474			4,474
Consumer	2				193,569				193,571			1			3,327			3,328
Total loans	$	36,821			$	2,376,077			$	2,412,898		$	1,593		$	27,284		$	28,877
The following table presents loans individually evaluated for impairment by segment of loans at March 31, 2014 and September 30, 2013:
	31-Mar-14											30-Sep-13
	Unpaid				Recorded				Related allowance			Unpaid			Recorded			Related allowance
	principal				investment							principal			investment
	balance											balance
With no related allowance recorded:
Commercial & industrial	$	1,841			$	1,841			$	—		$	2,175		$	2,131		$	—
Factored receivables	992				992				—			—			—			—
Commercial real estate	12,847				12,732				—			12,451			11,820			—
Acquisition, development & construction	21,915				21,005				—			17,971			17,945			—
Residential mortgage	515				515				—			515			515			—
Subtotal	38,110				37,085				—			33,112			32,411			—
With an allowance recorded:
Commercial & industrial	—				—				—			500			500			249
Commercial real estate	—				—				—			3,150			2,271			803
Acquisition, development & construction	—				—				—			2,753			1,637			540
Consumer	—				—				—			2			2			1
Subtotal	—				—				—			6,405			4,410			1,593
Total	$	38,110			$	37,085			$	—		$	39,517		$	36,821		$	1,593
During the quarter ended March 31, 2014, the Company modified its allowance for loan loss policy to generally require the charge-off of loan amounts identified as impaired.
The following table presents the average recorded investment and interest income recognized related to loans individually evaluated for impairment by segment for the three and six months ended March 31, 2014 and 2013:
	For the three months ended March 31, 2014											For the three months ended March 31, 2013
	QTD				Interest				Cash-basis			QTD			Interest			Cash-basis
	average				income				interest			average			income			interest
	recorded				recognized				income			recorded			recognized			income
	investment								recognized			investment						recognized
With no related allowance recorded:
Commercial & industrial	$	1,850			$	—			$	—		$	1,873		$	45		$	21
Factored receivables	992				—				—			—			—			—
Commercial real estate	12,512				40				—			9,248			99			53
Multi-family	264				—				—			—			—			—
Acquisition, development & construction	21,940				66				—			15,582			313			161
Residential mortgage	515				—				—			7,978			100			52
Consumer	—				—				—			2,127			7			3
Subtotal	38,073				106				—			36,808			564			290
With an allowance recorded:
Commercial & industrial	—				—				—			368			3			3
Commercial real estate	—				—				—			6,265			13			9
Residential mortgage	—				—				—			3,857			14			6
Acquisition, development & construction	—				—				—			649			—			—
Consumer	—				—				—			700			4			2
Subtotal	—				—				—			11,839			34			20
Total	$	38,073			$	106			$	—		$	48,647		$	598		$	310
	For the six months ended March 31, 2014											For the six months ended March 31, 2013
	YTD average				Interest				Cash-basis			YTD average			Interest			Cash-basis
	recorded				income				interest			recorded			income			interest
	investment				recognized				income			investment			recognized			income
									recognized									recognized
With no related allowance recorded:
Commercial & industrial	$	1,853			$	—			$	—		$	2,067		$	90		$	42
Factored receivables	496				—				—			—			—			—
Commercial real estate	12,204				94				—			9,241			199			105
Multi-family	264				—				—			—			—			—
Acquisition, development & construction	20,762				156				—			16,603			630			321
Residential mortgage	257				—				—			8,165			201			104
Consumer	—				—				—			2,198			14			6
Subtotal	35,836				250				—			38,274			1,134			578
With an allowance recorded:
Commercial & industrial	—				—				—			365			6			6
Commercial real estate	—				—				—			6,245			27			19
Residential mortgage	—				—				—			656			—			—
Acquisition, development & construction	—				—				—			3,885			27			12
Consumer	—				—				—			709			8			4
Subtotal	—				—				—			11,860			68			41
Total	$	35,836			$	250			$	—		$	50,134		$	1,202		$	619
Troubled Debt Restructuring:
The following tables set forth the amounts of the Company’s TDRs at March 31, 2014 and September 30, 2013:
	31-Mar-14
	Current loans				30-59				60-89			90+			Non-			Total
					days				days			days			accrual
					past due				past due			past due
Commercial & industrial	$	307			$	—			$	—		$	—		$	1,623		$	1,930
Commercial real estate	2,613				—				2,232			—			448			5,293
Acquisition, development & construction	6,090				272				—			—			6,956			13,318
Residential mortgage	5,492				969				—			—			2,868			9,329
Consumer	—				—				—			—			221			221
Total	$	14,502			$	1,241			$	2,232		$	—		$	12,116		$	30,091
Allowance for loan losses	$	52			$	—			$	—		$	—		$	14		$	66
	30-Sep-13
	Current loans				30-59				60-89			90+			Non-			Total
					days				days			days			accrual
					past due				past due			past due
Commercial & industrial	$	1,843			$	—			$	—		$	141		$	—		$	1,984
Commercial real estate	5,305				—				—			—			—			5,305
Acquisition, development & construction	14,190				—				—			—			151			14,341
Residential mortgage	2,416				—				—			—			1,792			4,208
Consumer	—				—				—			—			256			256
Total	$	23,754			$	—			$	—		$	141		$	2,199		$	26,094
Allowance for loan losses	$	438			$	—			$	—		$	—		$	439		$	877
The Company had outstanding commitments to lend additional amounts of $0 and $4,101 to customers with loans classified as TDRs as of March 31, 2014, and September 30, 2013, respectively.
The following table presents loans by segment modified as TDRs that occurred during the three months ended March 31, 2014 and 2013:
	March 31, 2014										31-Mar-13
				Recorded investment									Recorded investment
	Number			Pre-				Post-			Number		Pre-			Post-
				modification				modification					modification			modification
Commercial & industrial	—			$	—			$	—		2		$	169		$	169
Acquisition, development & construction	2			1,060				1,060			5		3,049			3,049
Total restructured loans	2			$	1,060			$	1,060		7		$	3,218		$	3,218
The following table presents loans by segment modified as TDRs that occurred during the six months ended March 31, 2014 and 2013:
	March 31, 2014										31-Mar-13
				Recorded investment									Recorded investment
	Number			Pre-				Post-			Number		Pre-			Post-
				modification				modification					modification			modification
Commercial & industrial	—			$	—			$	—		3		$	1,669		$	1,669
Commercial real estate & multi-family	—			—				—			1		450			450
Acquisition, development & construction	2			1,060				1,060			7		5,772			5,772
Residential mortgage	—			—				—			1		275			275
Total restructured loans	2			$	1,060			$	1,060		12		$	8,166		$	8,166
The TDRs presented above did not increase the allowance for loan losses for the three months ended March 31, 2014 or 2013. There were $736 charge-offs as a result of the above TDRs for the quarter ended March 31, 2014 and $0 for the quarter ended March 31, 2013.
The TDRs presented above increased the allowance for loan losses by $0 and $218 for the six months ended March 31, 2014 and 2013, respectively. There were $736 and $0 of charge-offs as a result of the above TDRs for the six months ended March 31, 2014 and 2013, respectively.
Credit Quality Indicators
As part of the on-going monitoring of the credit quality of the Company’s loan portfolio, management tracks certain credit quality indicators including trends related to (i) the weighted-average risk grade of commercial loans, (ii) the level of classified commercial loans, (iii) the delinquency status of consumer loans (residential mortgage and home equity lines of credit (“HELOC”)), (iv) net charge-offs, (v) non-performing loans (see details above) and (vi) the general economic conditions in the greater New York metropolitan region. The Bank analyzes loans individually by classifying the loans as to credit risk, except residential mortgage loans and consumer loans which are evaluated on a homogeneous basis unless the loan balance is greater than $500. This analysis is performed on at least a quarterly basis on all criticized/classified loans. The Bank uses the following definitions of risk ratings:
1 and 2 - These grades include loans that are secured by cash, marketable securities or cash surrender value of life insurance policies.
3 - This grade includes loans to borrowers with strong earnings and cash flow and that have the ability to service debt. The borrower’s assets and liabilities are generally well matched and are above average quality. The borrower has ready access to multiple sources of funding including alternatives such as term loans, private equity placements or trade credit.
4 - This grade includes loans to borrowers with above average cash flow, adequate earnings and debt service coverage ratios. The borrower generates discretionary cash flow, assets and liabilities are reasonably matched, and the borrower has access to other sources of debt funding or additional trade credit at market rates.
5 - This grade includes loans to borrowers with adequate earnings and cash flow and reasonable debt service coverage ratios. Overall leverage is acceptable and there is average reliance upon trade debt. Management has a reasonable amount of experience and modest debt owners are willing to invest available, outside capital as necessary.
6 - This grade includes loans to borrowers where there is evidence of some strain, earnings are inconsistent and volatile, and the borrowers’ outlook is uncertain. Generally such borrowers have higher leverage than those with a better risk rating. These borrowers typically have limited access to alternative sources of bank debt and may be dependent upon funding for working capital support.
7 - Special Mention (OCC definition) - Other Assets Especially Mentioned (OAEM) are loans that are currently protected but are potentially weak. Loans with special mention ratings have potential weaknesses which may, if not reviewed or corrected, weaken the asset or inadequately protect the Bank’s credit position at some future date. Such assets constitute an undue and unwarranted credit risk but not to the point of justifying a classification of substandard. The credit risk may be relatively minor yet constitute an unwarranted risk in light of the circumstances surrounding a specific asset.
8 - Substandard (OCC definition) - These loans are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified must have a well-defined weakness that jeopardizes the liquidation of the debt. They are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected. Loss potential, while existing in the aggregate amount of substandard assets, does not have to exist in individual assets classified as substandard.
9 - Doubtful (OCC definition) - These loans have all the weakness inherent in one classified as substandard with the added characteristics that the weakness makes collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. The possibility of loss is extremely high, but because of certain important and reasonably specific pending factors which may work to the advantage and strengthening of the asset, its classification as an estimated loss is deferred until its more exact status may be determined. Pending factors include proposed merger, acquisition, or liquidating procedures, capital injection, perfecting liens or additional collateral and refinancing plans.
10 - Loss (OCC definition) - These loans are charged-off because they are determined to be uncollectible and unbankable assets. This classification does not reflect that the asset has no absolute recovery or salvage value, but rather it is not practical or desirable to defer writing off this asset even though partial recovery may be effected in the future. Losses should be taken in the period in which they are determined to be uncollectible.
Loans that are risk-rated 1 through 6 as defined above are considered to be pass-rated loans. As of March 31, 2014 and September 30, 2013, the risk category of gross loans by segment was as follows:
	March 31, 2014											September 30, 2013
	Special				Substandard				Doubtful			Special			Substandard			Doubtful
	mention											mention
Commercial & industrial	$	25,620			$	7,731			$	2		$	3,545		$	3,855		$	365
Factored receivables	1,743				992				—			—			—			—
Equipment financing	—				276				—			—			—			—
Commercial real estate	8,813				33,627				—			7,279			24,561			227
Multi-family	—				617				—			—			—			—
Acquisition, development & construction	1,060				18,555				—			1,867			19,410			—
Residential mortgage	1,805				15,732				—			824			9,786			—
Consumer	923				5,141				—			15			2,891			—
Total	$	39,964			$	82,671			$	2		$	13,530		$	60,503		$	592

Deposits

Deposits	6 Months Ended
	Mar. 31, 2014
Deposits [Abstract]	'
Deposits	'
	Deposits
	Deposit balances are summarized as follows:
		March 31,		September 30,
		2014		2013
	Non-interest bearing demand	$	1,687,775	$	943,934
	Interest bearing demand	744,701		434,398
	Savings	607,601		580,125
	Money market	1,637,838		735,709
	Certificates of deposit	533,809		268,128
	Total deposits	$	5,211,724	$	2,962,294
	Municipal deposits totaled $926,618 and $757,066 at March 31, 2014 and September 30, 2013, respectively. See Note 3. Securities, for the amount of securities that were pledged as collateral for municipal deposits and other purposes.
	Summarized below are the Company’s brokered deposits included in the table above:
		March 31,		September 30,
		2014		2013
	Money market	$	59,131	$	34,571
	Reciprocal CDARs(1)	33,243		1,343
	CDARs one way	3,257		768
	Total brokered deposits	$	95,631	$	36,682
	(1)  Certificate of deposit account registry service.

Borrowings

Borrowings	6 Months Ended
	Mar. 31, 2014
Debt Instruments [Abstract]	'
Borrowings	'
	FHLB and other borrowings
	The Company’s FHLB and other borrowings and weighted average interest rates are summarized below:
		March 31, 2014				September 30, 2013
		Amount		Rate		Amount		Rate
	By type of borrowing:
	FHLB borrowings	$	489,801	2.34	%	$	442,602	2.77	%
	Repurchase agreements	19,991		0.36		20,351		0.88
	Senior Notes	98,215		5.98		98,033		5.98
	Total borrowings	$	608,007	2.86	%	$	560,986	3.26	%
	By remaining period to maturity:
	One year or less	$	109,328	1.01	%	$	158,897	0.95	%
	One to two years	145,224		0.56		78,717		1.97
	Two to three years	132,614		3.43		191		5.32
	Three to four years	120,000		4.1		202,414		4.21
	Four to five years	98,215		5.98		118,033		5.57
	Greater than five years	2,626		4.92		2,734		4.92
	Total borrowings	$	608,007	2.86	%	$	560,986	3.26	%
	As a member of the FHLB, the Bank may borrow in the form of term and overnight borrowings up to the amount of eligible mortgages and securities that have been pledged as collateral under a blanket security agreement. As of March 31, 2014 and September 30, 2013, the Bank had pledged mortgage loans totaling $924,115 and $784,422, respectively. The Bank had also pledged securities to secure borrowings, which are disclosed in Note 3. Securities. As of March 31, 2014, the Bank may increase its borrowing capacity by pledging securities and mortgage loans not required to be pledged for other purposes with a market value of $720,074.
	FHLB borrowings which are putable quarterly at the discretion of the FHLB were $200,000 as of March 31, 2014 and September 30, 2013. These borrowings have a weighted average remaining term to the contractual maturity dates of approximately 3.06 years and 3.56 years, respectively, and a weighted average interest rate of 4.23% at each of March 31, 2014 and September 30, 2013.
	The Bank had two $10,000 repurchase agreements at September 30, 2013 which were repaid in the quarter ended March 31, 2014. These repurchase agreements were acquired in connection with the Gotham transaction.
	The Company also assumed repurchase agreements in the Merger. At March 31, 2014, total repurchase agreements outstanding were $19,991, with a weighted average interest rate of 0.36% and a weighted average term to maturity of 20 days. The Bank has pledged investment securities as collateral for these borrowings (see Note 3. Securities).
	On July 2, 2013, the Company issued $100,000 principal amount of 5.50% fixed rate obligations (the “Senior Notes”) through a private placement at a discount of 1.75%. The cost of issuance was $303, and at March 31, 2014 and September 30, 2013 the unamortized discount was $1,785 and $1,967, respectively, which will be accreted to interest expense over the life of the Senior Notes, resulting in an all-in cost of 5.98%. Interest is due semi-annually in arrears on January 2 and July 2 of each year beginning January 2, 2014 until maturity on July 2, 2018. The Senior Notes were issued under an indenture (the “Indenture”) between the Company and U.S. Bank National Association, as trustee.
	The Senior Notes are unsecured obligations of the Company and rank equally with all other unsecured unsubordinated indebtedness, and will be effectively subordinated to any secured indebtedness to the extent of the value of the collateral securing such indebtedness, and structurally subordinated to the existing and future indebtedness of the Company’s subsidiaries.
	The indenture includes provisions that, among other things, restrict the Company’s ability to dispose of or issue shares of voting stock of a principal subsidiary bank (as defined in the Indenture) or transfer the entirety of or a substantial amount of the Company’s assets or merge or consolidate with or into other entities, without satisfying certain conditions.
	The Senior Notes will not be registered under the Securities Act and may not be offered or sold in the U.S. absent registration or an applicable exemption from registration requirements.

Subordinated_Debentures

Subordinated Debentures	6 Months Ended
	Mar. 31, 2014
Subordinated Debentures [Abstract]	'
Subordinated Borrowings Disclosure [Text Block]	'
	Subordinated Debentures
		March 31, 2014		September 30, 2013
	Subordinated debentures	$	25,774	$	—
	Premium recorded to reflect fair value at acquisition date	735		—
		$	26,509	$	—
	In February 2002, legacy Sterling issued $25,000 of trust preferred capital securities. The capital securities which are due March 31, 2032 and bear interest at 8.375%, were issued by Sterling Bancorp Trust I, a wholly-owned, non-consolidated statutory business trust. The trust was formed with initial capitalization of common stock and for the exclusive purpose of issuing the capital securities. The trust used the proceeds from the issuance of the capital securities to acquire $25,774 junior subordinated debenture securities that pay interest at 8.375% issued by the Company. The Company is not considered the primary beneficiary of the trust (which is a VIE); therefore, the trust is not consolidated in the Company’s financial statements, but rather the subordinated debentures are recorded as a liability. The debt securities are due concurrently with the capital securities, which may be redeemed at a price equal to their principal amount plus interest accrued to the date of redemption at par. The Company may also reduce outstanding capital securities, through open market purchases. At March 31, 2014, the Company held $1,013 par value of the capital securities as available for sale investment securities.
	The capital securities held by the Company are considered to be outstanding for the payment of dividends but are considered to be redeemed for the calculation of regulatory capital ratios. The $23,987 of capital securities not held by the Company is included in Tier 1 capital for regulatory capital purposes as allowed by the Federal Reserve Board.
	The premium on the securities represents the adjustment to reflect the fair value of the securities at the date of the Merger. This premium will be amortized as a reduction of interest expense over the remaining term of the capital securities on a level yield basis.
	On April 30, 2014, the Company announced that it will redeem the capital securities on June 1, 2014 at a redemption price equal to 100% of the liquidation amount of the securities plus accumulated and unpaid interest, with such redemption payment made on June 2, 2014. In connection with the redemption, the Company will eliminate the unamortized premium recorded to reflect the fair value of the subordinated debentures at the date of the Merger. The balance of the unamortized premium was $735 at March 31, 2014. This amount will be recognized as a gain on extinguishment of debt and recorded as other non-interest income in the quarter ending June 30, 2014.

Guarantors_Obligations_Under_G

Guarantor's Obligations Under Guarantees	6 Months Ended
	Mar. 31, 2014
Guarantees [Abstract]	'
Guarantor's Obligations Under Guarantees	'
	Guarantor’s Obligations Under Guarantees
	Most letters of credit issued by or on behalf of the Company are standby letters of credit. Standby letters of credit are commitments issued by the Company on behalf of its customer/obligor in favor of a beneficiary that specify an amount the Company can be called upon to pay upon the beneficiary’s compliance with the terms of the letter of credit. These commitments are primarily issued in favor of local municipalities to support the obligor’s completion of real estate development projects. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers.
	As of March 31, 2014, the Company had $75,931 in outstanding letters of credit, of which approximately $21.0 million are cash-secured and approximately $14.0 million were secured by other collateral. The carrying values of these obligations are not considered material.

Contingencies

Contingencies	6 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Contingencies	'
	Contingencies
	Certain premises and equipment are leased under operating leases with terms expiring through 2033. The Company has the option to renew certain of these leases for additional terms.
	Litigation
	The Company and the Bank are involved in a number of judicial proceedings concerning matters arising from conducting their business activities. These proceedings include actions brought against the Company and the Bank with respect to corporate matters and transactions in which the Company and the Bank were involved. In addition, the Company and the Bank may be requested to provide information or otherwise cooperate with government authorities in the conduct of investigations of other persons or industry groups.
	There can be no assurance as to the ultimate outcome of a legal proceeding; however, the Company and the Bank have generally denied, or believe we have meritorious defenses and will deny, liability in all significant litigation pending against us, including the matters described below, and we intend to defend vigorously each case, other than matters we describe as having settled. We accrue a liability for legal claims when payments associated with the claims become probable and the costs can be reasonably estimated. The actual costs of resolving legal claims may be substantially higher or lower than the amounts accrued for those claims.
	As previously disclosed on April 9, 2013, the first of seven actions, captioned Altman v. Sterling Bancorp, et al., Index No. 651263/2013 (N.Y. Sup. Ct., N.Y. County, 2013), was filed in the New York State Supreme Court, New York County, on behalf of a putative class of shareholders against legacy Sterling, its directors, and the Company.  On May 17, 2013, the seven actions were consolidated under the caption In re Sterling Shareholders Litigation, Index No. 651263/2013 (N.Y. Sup. Ct., N.Y. County, 2013). On June 21, 2013, the lead plaintiffs filed a consolidated and amended class action complaint alleging that legacy Sterling’s board of directors breached its fiduciary duties by agreeing to the Merger transaction described in Note 2 and by failing to disclose all material information to shareholders. The consolidated and amended complaint also alleged that the Company aided and abetted those alleged fiduciary breaches. The action sought, among other things, equitable relief and/or money damages.
	Also as previously disclosed, on June 5, 2013, substantially similar litigation was filed in the United States District Court for the Southern District of New York, captioned Miller v. Sterling Bancorp, et al., No. 13‑3845 (S.D. N.Y. 2013), against legacy Sterling, its directors, and the Company on behalf of the same putative class of legacy Sterling shareholders. The complaint alleged the same breach of fiduciary duty and aiding and abetting claims against defendants, and also alleged defendants’ preliminary proxy statement was inaccurate or incomplete in violation of Sections 14(a) and 20(a) of the Securities Exchange Act of 1934, as amended.
	In terms of material developments on the status of proceedings, on September 12, 2013, the Company and the parties entered into a memorandum of understanding regarding the settlement of the lawsuits under which each of the actions will be dismissed with prejudice. Pursuant to the terms of the settlement, the Company agreed to make certain supplemental disclosures related to the Merger.  The settlement is subject to, among other things, entry into final, definitive documentation and approval by the New York State Supreme Court. The Court has scheduled a hearing on June 25, 2014 to determine, among other things, whether to approve the proposed settlement.

Earnings_Per_Common_Share

Earnings Per Common Share	6 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings Per Common Share	'
	Earnings Per Common Share
	The number of shares used in the computation of basic earnings per share excluded unallocated Employee Stock Ownership Plan shares (the ESOP plan was terminated on February 4, 2014) and unvested shares of restricted stock that are not participating securities.
	Common stock equivalent shares are incremental shares (computed using the treasury stock method) that would have been outstanding if all potentially dilutive stock options and unvested recognition and retention plan shares were exercised or became vested during the periods presented.
	Basic earnings per common share are computed as follows:
		For the three months ended March 31,				For the six months ended March 31,
		2014		2013		2014			2013
	Weighted average common shares outstanding (basic)	83,497,765		43,743,640		76,924,082			43,704,163
	Net income (loss)	$	10,332	$	6,529	$	(3,671	)	$	13,549
	Basic earnings (loss) per common share	0.12		0.15		(0.05		)	0.31
	Diluted earnings per common share are computed as follows:
		For the three months ended March 31,				For the six months ended March 31,
		2014		2013		2014			2013
	Weighted average common shares outstanding (basic)	83,497,765		43,743,640		76,924,082			43,704,163
	Effect of common stock equivalents	296,342		104,846		—			86,752
	Weighted average common shares outstanding (diluted)	83,794,107		43,848,486		76,924,082			43,790,915
	Net income (loss)	$	10,332	$	6,529	$	(3,671	)	$	13,549
	Diluted earnings (loss) per common share	0.12		0.15		(0.05		)	0.31
	As of March 31, 2014 and 2013, 653,146 and 1,332,619 weighted average common shares that could be exercised under stock option plans were anti-dilutive for the three month periods, respectively. As of March 31, 2014 and 2013, 849,188 and 1,344,024 weighted average common shares that could be exercised under stock option plans were anti-dilutive for the six month periods, respectively. Anti-dilutive shares are not included in determining diluted earnings per share.

Other_Noninterest_expense

Other Non-interest expense	6 Months Ended
	Mar. 31, 2014
Other Non-Interest Expense [Abstract]	'
Other non-interest expense [Text Block]	'
	Other Non-Interest Expense
	Other non-interest expense items are presented in the following table. Components exceeding 1% of the aggregate of total net interest income and total non-interest income are presented separately.
		For the three months ended March 31,				For the six months ended March 31,
		2014		2013		2014		2013
	Other non-interest expense:
	Advertising and promotion	$	422	$	535	731		779
	Professional fees	1,500		912		3,319		2,128
	Data and check processing	663		823		1,258		1,471
	Insurance - general	637		213		1,217		468
	Other	4,852		1,820		9,426		4,130
	Total other non-interest expense	$	8,074	$	4,303	$	15,951	$	8,976

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company has three active stock-based compensation plans as described below. Total compensation expense that was charged against income for these plans was $927 and $679, for the three months ended March 31, 2014 and 2013, respectively. There was no income tax benefit realized in these periods.
	Total compensation expense that was charged against income for these plans was $1,918 and $1,179, for the six months ended March 31, 2014 and 2013, respectively. There was no income tax benefit realized in these periods.
	Active Stock-Based Compensation Plans
	The Company’s stockholders approved the 2014 Stock Incentive Plan (the “2014 Plan”) on February 20, 2014. The 2014 Plan permits the grant of stock options, stock appreciation rights, restricted stock (both time-based and performance-based), restricted stock units, performance units, deferred stock, and other stock-based awards for up to 3,400,000 shares of common stock as of March 31, 2014.
	The Company’s 2012 Stock Incentive Plan (the “2012 Plan”), is a shareholder-approved plan that permits the grant of stock options, stock appreciation rights, restricted stock (both time-based and performance-based), restricted stock units, performance units, deferred stock and other stock-based awards for up to 1,557,622 shares of common stock as of March 31, 2014.
	The Company’s 2004 Stock Incentive Plan (the “2004 Plan”), is a shareholder-approved plan that permits the grant of stock options to its employees for up to 230,281 shares of common stock as of March 31, 2014.
	Under the terms of the plans above, stock option awards are granted with a fair value equal to the market price of the Company’s common stock at the date of grant; the awards generally vest in equal installments annually on the anniversary date and have total vesting periods ranging from 2 to 5 years and stock options have 10 year contractual terms. The Company has a policy of using shares held as treasury stock to satisfy its stock-based compensation stock issuances. Currently, the Company has a sufficient number of treasury shares to satisfy expected stock based compensation issuances.
	The Company’s 2004 Restricted Stock Plan, which historically has been referred to as the Recognition and Retention Plan (“RRP”), provides for the issuance of shares to directors and officers. Compensation expense is recognized on a straight-line basis over the vesting period of the awards based on the fair value of the stock at issue date. RRP shares vest annually on the anniversary of the grant date over the vesting period. Total shares remaining that are authorized and available for future grant under the RRP are 77 at March 31, 2014.
	Under the 2014 Plan any shares that are subject to stock options or stock appreciation rights are counted as one share deducted from the 2014 Plan for every one share delivered under those awards. Any shares granted under the 2014 Plan that are subject to awards other than stock options and stock appreciation rights are counted as 3.5shares deducted from the 2014 Plan for every one share delivered under those awards. Under the 2012 Plan each share of restricted stock (or non-vested stock awards,) is counted as 3.6 shares deducted from the 2012 Plan for every one share delivered under those awards. Under the 2012 Plan, shares awarded under other grants, including stock options, stock appreciation rights, performance units, deferred stock and other stock awards will count as one share deducted from the plan for every one share delivered under those awards. Under the 2004 Plan and the RRP each grant of stock or restricted stock counts as one share deducted from the applicable plan for every one share delivered under those awards.
	In connection with the Merger, the Company granted 110,470 options at an exercise price of $14.25 per share pursuant to a Registration Statement on Form S-8 under which the Company assumed all outstanding fully vested legacy Sterling stock options. Substantially all of these options expire March 15, 2017. During the six months ended March 31, 2014, 9,468 of these awards were canceled or forfeited and such shares are again available for grant. The Company also granted 95,991 shares under the Sterling Bancorp 2013 Employment Inducement Award Plan to certain executive officers of legacy Sterling. In addition, the Company issued 255,973 shares of restricted stock from shares available under the Company’s 2012 Plan to certain executives of legacy Sterling. The weighted average grant date fair value was $11.72 per share and the restricted stock awards vest in equal annual installments on the anniversary date over a three-year period.
	The fair value of each stock option award is estimated on the date of grant using a closed form option valuation (Black-Scholes) model that uses the assumptions noted in the table below. Expected volatility is based on the historical volatility of the Company’s common stock. The expected term of options granted is based on historical data and represents the period of time that options granted are expected to be outstanding, which takes into account that the options are not transferable. The risk-free interest rate for the expected term of the option is based on the U.S. Treasury yield curve in effect at the date of grant.
	The fair value of options granted was determined using the following weighted average assumptions as of the grant date:
		For the six months ended March 31,
		2014		2013
	Risk-free interest rate	1.74	%	0.96	%
	Expected stock price volatility	26.5	%	40.8	%
	Dividend yield (1)	2.05	%	2.61	%
	Expected term in years	5.75		5.75
	(1) Represents the approximate annualized cash dividend rate paid with respect to a share of common stock at or near the grant date.
	The following table summarizes the combined activity in the Company’s stock-based compensation plans for the six months ended March 31, 2014:
				Non-vested stock awards/stock units outstanding				Stock options outstanding
		Shares available for grant		Number of shares		Weighted average grant date fair value		Number of shares		Weighted average exercise price
	Balance at September 30, 2013	2,066,184		209,697		$	8.73	2,114,509		$	10.71
	2014 Stock Incentive Plan	3,400,000		—		—		—		—
	Grants associated with the Merger(1)	(921,503	)	351,964		11.72		104,152		14.25
	Granted (1)	(595,435	)	101,078		11.36		249,862		11.36
	Stock awards vested	—		(46,590	)	8.75		—		—
	Exercised	—		—		—		(432,056	)	11.79
	Forfeited	331,694		(15,996	)	8.86		(274,109	)	12.08
	Canceled/expired	(5,000	)	—		—		—		—
	Balance at March 31, 2014	4,275,940		600,153		$	10.89	1,762,358		$	10.53
	Exercisable at March 31, 2014							1,058,882		$	11.24
	(1) Reflects certain non-vested stock awards that count as 3.5 shares deducted from the plan for every one share delivered under these awards.
	The weighted average fair value of options granted was $2.49 and $2.74 for the six months ended March 31, 2014 and 2013, respectively.
	As of March 31, 2014, there was $1,422 of total unrecognized compensation expense related to non-vested stock options granted under the Company’s stock-based compensation plans. The expense is expected to be recognized over a weighted average period of 1.83 years.
	As of March 31, 2014, there was $5,192 of total unrecognized compensation expense related to non-vested restricted shares granted under the 2012 Plan, the RRP and the Registration Statement on Form S-8. The expense is expected to be recognized over a weighted average period of 2.27 years.
	There were no stock-based award modifications for the six months ended March 31, 2014 and 2013.

Pension_and_Other_Post_Retirem

Pension and Other Post Retirement Plans	6 Months Ended
	Mar. 31, 2014
Compensation Related Costs [Abstract]	'
Pension and Other Post Retirement Plans	'
	Pension and Other Post Retirement Plans
	Net pension expense for the three months and six months ended March 31, 2014 was incurred for the Provident Bank Benefit Pension Plan (the “legacy Provident Plan”) and legacy Sterling/Sterling National Bank employees’ Retirement Plan (the “legacy Sterling Plan”). Net pension expense and and post-retirement expense, which is recorded in compensation and employee benefits expense in the consolidated statements of operations, is comprised of the following:
		Pension plan						Other post
								retirement plans
		For the three months ended March 31,						For the three months ended March 31,
		2014			2013			2014		2013
	Service cost	$	—		$	—		$	—	$	11
	Interest cost	1,377			363			11		31
	Expected return on plan assets	(1,701		)	(615		)	32		—
	Amortization of net transition obligation	—			—			6		6
	Amortization of prior service cost	—			—			12		12
	Amortization of (gain) or loss	48			515			—		(6		)
	Charge for settlement of a portion of defined benefit plan	1,352			—			—		—
	Total cost	$	1,076		$	263		$	61	$	54
		Pension plan						Other post
								retirement plans
		For the six months ended March 31,						For the six months ended March 31,
		2014			2013			2014		2013
	Service cost	$	—		$	—		$	—	$	23
	Interest cost	1,779			726			23		63
	Expected return on plan assets	(2,372		)	(1,231		)	66		—
	Amortization of net transition obligation	—			—			12		12
	Amortization of prior service cost	—			—			24		23
	Amortization of (gain) or loss	145			1,031			—		(13		)
	Charge for settlement of a portion of defined benefit plan	4,095			—			—		—
	Total cost	$	3,647		$	526		$	125	$	108
	In connection with the Merger, the Company assumed the following pension liabilities on October 31, 2013:
	•	A liability for the legacy Sterling Supplemental Executive Retirement Plan (the “legacy Sterling SERP”) for designated participants. The balance of the liability assumed was $41,412 and was settled through a cash payment to the designated participants on November 8, 2013.
	•	A liability for the legacy Sterling Plan.  The legacy Sterling Plan is a defined benefit plan that covers eligible employees of legacy Sterling and legacy Sterling National Bank and certain of its subsidiaries who were hired prior to January 3, 2006 and who attained age 21 prior to January 3, 2007. Effective October 31, 2013, the legacy Sterling Plan was amended and the accrued benefit of each eligible actively employed participant that had not yet commenced benefits was increased by approximately 4.4% and the accrual of future service benefits ceased.
	•	A liability for the legacy Sterling life insurance benefits provided to certain officers.  The level of coverage provided is determined upon years of service with legacy Sterling and the Company and the employee’s date of retirement.  The Company’s post-retirement benefit plan is unfunded and the liability at March 31, 2014 was $8,932. For the three and six months ended March 31, 2014, the Company recognized an expense of $134 and $204 related to legacy Sterling’s post-retirement benefit plan.
	As of March 31, 2014, the Company does not anticipate that additional contributions will be made during the remainder of fiscal year 2014 to the legacy Provident or legacy Sterling Plans. The Company is in the process of merging the plans. The legacy Provident pension plan liability was $31,705 at September 30, 2013. During the first six months ended March 31, 2014, the Company settled a portion of its pension plan liability through the acquisition of annuity contracts from a nationally recognized insurance company in the amount of $13,698, which together with the net amount of benefits paid and interest cost reduced the pension plan liability to $19,466 at March 31, 2014.   The legacy Provident Plan’s over funded status decreased from $3,712 at September 30, 2013 to $3,096 at March 31, 2014. In connection with the settlement discussed above, the Company incurred accelerated amortization of its accumulated other comprehensive loss on the defined benefit plan in the amount of $2,743, which was realized through earnings as part of Non-interest expense - Compensation and benefits during the six months ended March 31, 2014.
	On March 28, 2014 the Company settled a portion of the legacy Sterling Plan liability through the acquisition of annuity contracts from a nationally recognized insurance company in the amount of $28,835, which reduced the pension plan liability to $27,946 at March 31, 2014. At March 31, 2014, the legacy Sterling Qualified Plan had assets of approximately $44.7 million and the legacy Sterling Plan was over funded by approximately $16.7 million. The prepaid pension asset related to the legacy Sterling Plan is recorded in other assets on the Company’s balance sheet. For the three and six months ended March 31, 2014, the Company recognized an expense of $1,208 related to the legacy Sterling Plan, comprised of a termination charge of $1,352 and a pension benefit of ($144).
	The Company has also established a non-qualified Supplemental Executive Retirement Plan (“SERP”) to provide certain executives with supplemental retirement benefits in addition to the benefits provided by the pension plan due to amounts limited by the Internal Revenue Code of 1986, as amended (“IRS Code”). The periodic pension expense for the SERP amounted to $61 for the three months ended March 31, 2014 and $54 for the three months ended March 31, 2013. The periodic pension expense for the SERP amounted to $125 for the six months ended March 31, 2014 and $101 for the six months ended March 31, 2013. The liability for the SERP was $1,141 and $1,203 at March 31, 2014 and September 30, 2013, respectively. For the three months ended March 31, 2014 and 2013 there was $95 and $9, respectively, in contributions to fund benefit payments related to the SERP. For the six months ended March 31, 2014 and 2013 there was $159 and $18, respectively, in contributions to fund benefit payments related to the SERP.
	On October 30, 2013,  the Company terminated its ESOP.  In accordance with the provisions of the plan, all participants received contributions for calendar year 2013 and became 100% vested in their accounts.  On February 4, 2014, the ESOP held 499,330 shares of the Company’s common stock.  Of these shares, 488,403 were used to retire the ESOP trust outstanding loan obligation, which was $5,983 including accrued interest.  In accordance with the provisions of the ESOP, the remaining 10,927 shares were allocated ratably to ESOP participants.  The Company incurred ESOP expense of $286 including a $134 plan termination charge during the six months ended March 31, 2014.

Derivatives

Derivatives	6 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedges, Assets [Abstract]	'
Derivatives	'
	Derivatives
	The Company purchased two interest rate caps in fiscal 2010 to assist in offsetting a portion of interest rate exposure should short- term rate increases lead to rapid increases in general levels of market interest rates on deposits. These caps are linked to LIBOR and have strike prices of 3.5% and 4.0%. These caps are stand alone derivatives and therefore changes in fair value are reported in current period earnings; there was no fair value gain or loss recorded for the three months ended March 31, 2014 and 2013. Losses recognized in earnings for the six months ended March 31, 2014 and 2013 were $0 and $1, respectively. The fair value of the interest rate caps at March 31, 2014, is reflected in other assets with a corresponding credit (charge) to income recorded as a gain (loss) to non-interest income.
	The Company has entered into certain interest rate swap contracts that are not designated as hedging instruments. These derivative contracts relate to transactions in which the Company enters into an interest rate swap with a customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each swap transaction, the Company agrees to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a similar notional amount at a fixed interest rate. At the same time, the Company agrees to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows the Company’s customer to effectively convert a variable rate loan to a fixed rate. Because the Company acts as an intermediary for its customer, changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact the Company’s results of operations.
	The Company pledged collateral to another financial institution in the form of investment securities with an amortized cost of $5,037 and a fair value of $4,700 as of March 31, 2014. The Company does not typically require its commercial customers to post cash or securities as collateral on its program of back-to-back swaps. However, certain language is written into the International Swaps and Derivatives Association agreement and loan documents where, in default situations, the Company is allowed to access collateral supporting the loan relationship to recover any losses suffered on the derivative asset or liability. The Company may need to post additional collateral in the future in proportion to potential increases in unrealized loss positions.
	Summary information regarding these derivatives is presented below:
		Notional			Average	Weighted		Weighted average	Fair value
		amount			maturity (in years)	average		variable rate
						fixed rate
	At March 31, 2014
	Interest rate caps	$	50,000		0.68	3.75	%	NA	$	—
	Third-party interest rate swaps	53,141			5.26	4.22		1 m Libor + 2.45	756
	Customer interest rate swaps	(53,141		)	5.26	4.22		1 m Libor + 2.45	(756		)
	At September 30, 2013
	Interest rate caps	$	50,000		1.18	3.75	%	NA	$	—
	Third-party interest rate swaps	54,180			5.76	4.22		1 m Libor + 2.45	997
	Customer interest rate swaps	(54,180		)	5.76	4.22		1 m Libor + 2.45	(997		)
	The Company enters into various commitments to sell real estate loans in the secondary market. Such commitments are considered to be derivative financial instruments; however, the fair value of these commitments is not material.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair value measurements	'
	Fair Value Measurements
	Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. There are three levels of inputs that may be used to measure fair values.
	Level 1 Inputs – Unadjusted quoted prices in active markets for identical assets and liabilities that the reporting entity has the ability to access at the measurement date.
	Level 2 Inputs – Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risk etc.) or inputs that are derived principally from or corroborated by, market data by correlation or other means.
	Level 3 Inputs – Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities.
	In general, fair value is based on quoted market prices, when available. If quoted market prices in active markets are not available, fair value is based on internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value.  These adjustments may include amounts to reflect counterparty credit quality and the Company’s creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. The Company’s valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes the Company’s valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the reported fair value amounts have not been comprehensively revalued since the presentation dates, and therefore, estimates of fair value after the balance sheet date may differ significantly from the amounts presented herein. A more detailed description of the valuation methodologies used for assets and liabilities measured at fair value is set forth below. Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with the Company’s monthly and/or quarterly valuation process.
	Investment Securities Available for Sale
	The majority of the Company’s available for sale investment securities are reported at fair value utilizing Level 2 inputs. For these securities, the Company obtains fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the securities’ terms and conditions, among other things.
	The Company reviews the prices supplied by the independent pricing service, as well as their underlying pricing methodologies, for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, the Company does not purchase investment securities that have a complicated structure. The Company’s entire portfolio consists of traditional investments, nearly all of which are mortgage pass-through securities, state and municipal general obligation or revenue bonds, U.S. agency bullet and callable securities and corporate bonds. Pricing for such instruments is fairly generic and is easily obtained. From time to time, the Company validates, on a sample basis, prices supplied by the independent pricing service by comparison to prices obtained from third-party sources or derived using internal models.
	The Company reports the fair value of private label collateralized mortgage obligations or “CMOs” with a rating from a national recognized bond rating agency of below investment grade using Level 3 inputs. As of March 31, 2014, these securities have an amortized cost and fair value of $3.2 million, representing 17 basis points of our total investment portfolio. At March 31, 2014 we do not anticipate further OTTI charges on these securities. These securities along with all of the Company’s other securities will be reviewed on at least a quarterly basis to assess whether impairment, if any, is OTTI.
	Derivatives
	The fair values of derivatives are based on valuation models using current market terms (including interest rates and fees), the remaining terms of the agreements and the credit worthiness of the counter party as of the measurement date (Level 2). The Company’s derivatives consist of two interest rate caps and twelve interest rate swaps. See Note 14. Derivatives.
	Commitments to Sell Real Estate Loans
	The Company enters into various commitments to sell real estate loans in the secondary market. Such commitments are considered to be derivative financial instruments and therefore are carried at estimated fair value on the consolidated balance sheets. The estimated fair values of these commitments were generally calculated by reference to quoted prices in secondary markets for commitments to sell to certain government sponsored agencies. The fair values of these commitments generally result in a Level 2 classification. The fair value of these commitments is not material.
	A summary of assets and liabilities at March 31, 2014 measured at estimated fair value on a recurring basis is as follows:
		March 31, 2014
		Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
	Assets:
	Investment securities available for sale:
	Residential mortgage-backed securities:
	Agency-backed	$	457,515		$	—			$	457,515		$	—
	CMO/Other MBS	131,621			—				131,621			—
	Private label CMOs	3,230			—				—			3,230
	Total residential mortgage-backed securities	592,366			—				589,136			3,230
	Other securities:
	US Government	—			—				—			—
	Federal agencies	209,701			—				209,701			—
	Corporate bonds	222,198			—				222,198			—
	State and municipal	137,136			—				137,136			—
	Trust preferred	67,086			—				67,086			—
	Mutual funds	4,823			—				4,823			—
	Total other securities	640,944			—				640,944			—
	Total investment securities available for sale	1,233,310			—				1,230,080			3,230
	Interest rate caps and swaps	756			—				756			—
	Total assets measured at estimated fair value on a recurring basis	$	1,234,066		$	—			$	1,230,836		$	3,230
	Liabilities:
	Interest rate swaps	$	756		$	—			$	756		$	—
	Total liabilities measured at estimated fair value on a recurring basis	$	756		$	—			$	756		$	—
	A summary of assets and liabilities at September 30, 2013 measured at estimated fair value on a recurring basis is as follows:
		September 30, 2013
		Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
	Assets:
	Investment securities available for sale:
	Residential mortgage-backed securities:
	Agency-backed	$	282,529		$	—			$	282,529		$	—
	CMO/Other MBS	163,041			—				163,041			—
	Private label CMOs	3,613			—				—			3,613
	Total residential mortgage-backed securities	449,183			—				445,570			3,613
	Other securities:
	Federal agencies	261,547			—				261,547			—
	Corporate bonds	114,933			—				114,933			—
	State and municipal	128,730			—				128,730			—
	Total other securities	505,210			—				505,210			—
	Total investment securities available for sale	954,393			—				950,780			3,613
	Interest rate caps and swaps	997			—				997			—
	Total assets measured at estimated fair value on a recurring basis	$	955,390		$	—			$	951,777		$	3,613
	Liabilities:
	Interest rate swaps	$	997		$	—			$	997		$	—
	Total liabilities measured at estimated fair value on a recurring basis	$	997		$	—			$	997		$	—
	There were no transfers between Level 1 and Level 2 inputs during the six months ended March 31, 2014 and 2013.
	The following categories of financial assets are not measured at fair value on a recurring basis, but are subject to fair value adjustments in certain circumstances:
	Loans Held for Sale and Impaired Loans
	Mortgage loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value as determined by outstanding commitments from investors. Fair value of loans held for sale is determined using quoted prices for similar assets (Level 2 inputs).
When mortgage loans held for sale are sold with servicing rights retained, the carrying value of mortgage loans sold is reduced by the amount allocated to the value of the servicing rights which is equal to its fair value. Gains and losses on sales of mortgage loans are based on the difference between the selling price and the carrying value of the related loan sold.
The Company may record adjustments to the carrying value of loans based on fair value measurements for partial charge-offs of the uncollectible portions of these loans. These adjustments also include certain impairment amounts for collateral dependent loans calculated in accordance with FASB ASC Topic 310 – Receivables, when establishing the allowance for loan losses. Impairment amounts are generally based on the fair value of the underlying collateral supporting the loan and, as a result, the carrying value of the loan less the calculated impairment amount applicable to that loan does not necessarily represent the fair value of the loan. Real estate collateral is valued using independent appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable by market participants. However, due to the substantial judgment applied and limited volume of activity as compared to other assets, fair value is based on Level 3 inputs. Estimates of fair value used for collateral supporting commercial loans generally are based on assumptions not observable in the market place and are also based on Level 3 inputs. Impaired loans are evaluated on at least a quarterly basis for additional impairment and their carrying values are adjusted as needed. Loans subject to non-recurring fair value measurements were $37,085 and $35,230 (which equals the carrying value less the allowance for loan losses allocated to these loans) at March 31, 2014 and September 30, 2013, respectively. Changes in fair value recognized in provisions on loans held by the Company were $(447) and $1,815 for the six months ended March 31, 2014 and 2013, respectively.
When valuing impaired loans that are collateral dependent, the Company charges-off the difference between the recorded investment in the loan and the appraised value, which is generally less than 12 months old. A discount for estimated costs to dispose of the asset is used when evaluating the impaired loans.
A summary of impaired loans at March 31, 2014 measured at estimated fair value on a non-recurring basis is the following:
	March 31, 2014
	Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
Commercial real estate	897			—				—			897
Acquisition, development & construction	2,462			—				—			2,462
Total impaired loans measured at fair value	$	3,359		$	—			$	—		$	3,359
A summary of impaired loans at September 30, 2013 measured at estimated fair value on a non-recurring basis is the following:
	September 30, 2013
	Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
Commercial & industrial	$	500		$	—			$	—		$	500
Commercial real estate	3,672			—				—			3,672
Acquisition, development & construction	1,839			—				—			1,839
Consumer	2			—				—			2
Total impaired loans measured at fair value	$	6,013		$	—			$	—		$	6,013
Mortgage Servicing Rights
When mortgage loans are sold with servicing retained, servicing rights are initially recorded at fair value with the income statement effect recorded in net gain on sales of loans. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income.
The Company utilizes the amortization method to subsequently measure the carrying value of its servicing rights. In accordance with FASB ASC Topic 860 - Transfers and Servicing, the Company must record impairment charges on a non-recurring basis, when the carrying value exceeds the estimated fair value. To estimate the fair value of servicing rights, the Company utilizes a third-party, which on a quarterly basis, considers the market prices for similar assets and the present value of expected future cash flows associated with the servicing rights. Assumptions utilized include estimates of the cost of servicing, loan default rates, an appropriate discount rate and prepayment speeds. The determination of fair value of servicing rights relies upon Level 3 inputs. The fair value of mortgage servicing rights at March 31, 2014 and September 30, 2013 was $1,747 and $1,978, respectively.
Assets Taken in Foreclosure of Defaulted Loans
Assets taken in foreclosure of defaulted loans are initially recorded at fair value less costs to sell when acquired, which establishes a new cost basis. These assets are subsequently accounted for at the lower of cost or fair value less costs to sell and are primarily comprised of commercial and residential real estate property and upon initial recognition, are re-measured and reported at fair value through a charge-off to the allowance for loan losses based on the fair value of the foreclosed asset. The fair value is generally determined using appraisals or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the market place. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between comparable sales and income data available. The fair value is derived using Level 3 inputs. Appraisals are reviewed by our credit department, our external loan review consultant and verified by officers in our credit administration area. Assets taken in foreclosure of defaulted loans subject to non-recurring fair value measurement were $9,274 and $6,022 at March 31, 2014 and September 30, 2013, respectively. There were write-downs of $0 and $158 related to changes in fair value recognized through income for other real estate owned held by the Company during the three months ending March 31, 2014 and 2013, respectively.
There were write-downs of $224 and $606 related to changes in fair value recognized through income for other real estate owned held by the Company during the six months ending March 31, 2014 and 2013, respectively.
Significant Unobservable Inputs to Level 3 Measurements
The following table presents quantitative information about significant unobservable inputs used in the fair value measurements for Level 3 assets at March 31, 2014:
Non-recurring fair value measurements		Fair value			Valuation technique		Unobservable input / assumptions		Range(1) (weighted average)
Impaired loans:
Commercial real estate and multi-family		$	897		Appraisal		Adjustments for comparable properties		15.0% - 36.0% (22.0%)
Acquisition, development & construction		2,462			Appraisal		Adjustments for comparable properties		10.0% - 30.0% (13.5%)
Assets taken in foreclosure:
Commercial real estate		8,388			Appraisal		Adjustments by management to reflect current conditions/selling costs		20.0% - 37.0% (24.8%)
Residential mortgage		887			Appraisal		Adjustments by management to reflect current conditions/selling costs		16.0% - 59.0% (21.6%)
Mortgage servicing rights		1,747			Third-party valuation		Discount rate		9.3% - 12.8%
					Third-party valuation		Prepayment speed		100 - 968 (weighted average of 224)
(1) Represents range of discount factors applied to the appraisal to determine fair value. The amounts used for mortgage servicing rights are discounts applied by a third-party valuation provider which the Company believes are appropriate.
Fair Values of Financial Instruments
FASB Codification Topic 825 - Financial Instruments, requires disclosure of fair value information for those financial instruments for which it is practicable to estimate fair value, whether or not such financial instruments are recognized in the consolidated statements of financial condition for interim and annual periods. Fair value is the amount at which a financial instrument could be exchanged in a current transaction between willing parties, other than in a forced sale or liquidation.
Quoted market prices are used to estimate fair values when those prices are available, although active markets do not exist for many types of financial instruments. Fair values for these instruments must be estimated by management using techniques such as discounted cash flow analysis and comparison to similar instruments. These estimates are highly subjective and require judgments regarding significant matters, such as the amount and timing of future cash flows and the selection of discount rates that appropriately reflect market and credit risks. Changes in these judgments often have a material effect on the fair value estimates. Since these estimates are made as of a specific point in time, they are susceptible to material near-term changes. Fair values disclosed in accordance with FASB Topic 825 do not reflect any premium or discount that could result from the sale of a large volume of a particular financial instrument, nor do they reflect possible tax ramifications or estimated transaction costs.
The following is a summary of the carrying amounts and estimated fair values of financial assets and liabilities (none of which were held for trading purposes) as of March 31, 2014:
	March 31, 2014
	Carrying			Level 1 inputs				Level 2 inputs			Level 3 inputs
	amount
Financial assets:
Cash and due from banks	$	164,645		$	164,645			$	—		$	—
Securities available for sale	1,233,310			—				1,230,080			3,230
Securities held to maturity	527,265			—				527,121			—
Loans, net	4,212,339			—				—			4,254,200
Loans held for sale	21,348			—				21,348			—
Accrued interest receivable on securities	8,810			—				8,810			—
Accrued interest receivable on loans	9,344			—				—			9,344
FHLB stock and Federal Reserve Bank stock	53,346			—				—			—
Interest rate caps and swaps	756			—				756			—
Financial liabilities:
Non-maturity deposits	$	(4,677,915	)	$	(4,677,915	)		$	—		$	—
Certificates of deposit	(533,809		)	—				(533,733		)	—
FHLB and other borrowings	(489,801		)	—				(511,976		)	—
Other borrowings	(19,991		)	—				(19,992		)	—
Senior Notes	(98,215		)	—				(100,947		)	—
Subordinated debentures	(26,509		)	—				(26,149		)	—
Mortgage escrow funds	(8,711		)	—				(8,710		)	—
Accrued interest payable on deposits including escrow	(427		)	—				(427		)	—
Accrued interest payable on borrowings	(2,736		)	—				(2,736		)	—
Interest rate caps and swaps	(756		)	—				(756		)	—
The following is a summary of the carrying amounts and estimated fair values of financial assets and liabilities (none of which were held for trading purposes) as of September 30, 2013:
	September 30, 2013
	Carrying			Level 1 inputs				Level 2 inputs			Level 3 inputs
	amount
Financial assets:
Cash and due from banks	$	113,090		$	113,090			$	—		$	—
Securities available for sale	954,393			—				950,780			3,613
Securities held to maturity	253,999			—				250,896			—
Loans, net	2,384,021			—				—			2,422,824
Loans held for sale	1,011			—				1,011			—
Accrued interest receivable on securities	4,892			—				4,892			—
Accrued interest receivable on loans	6,805			—				—			6,805
FHLB stock	24,312			—				—			—
Interest rate caps and swaps	997			—				997			—
Financial liabilities:
Non-maturity deposits	(2,694,166		)	(2,694,166		)		—			—
Certificates of deposit	(268,128		)	—				(268,088		)	—
FHLB and other borrowings	(462,953		)	—				(488,369		)	—
Senior Notes	(98,033		)	—				(98,142		)	—
Mortgage escrow funds	(12,646		)	—				(12,644		)	—
Accrued interest payable on deposits including escrow	(1,480		)	—				(1,480		)	—
Accrued interest payable on borrowings	(1,525		)	—				(1,525		)	—
Interest rate caps and swaps	(997		)	—				(997		)	—
The following paragraphs summarize the principal methods and assumptions used by the Company to estimate the fair value of the Company’s financial instruments:
Loans
The estimated fair value approximates carrying value for variable-rate loans that reprice frequently and with no significant change in credit risk. The fair value of fixed-rate loans and variable-rate loans which reprice on an infrequent basis is estimated by discounting future cash flows using the current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality. An overall valuation adjustment is made for specific credit risks as well as general portfolio credit risk.
FHLB of New York Stock and Federal Reserve Bank Stock
The redeemable carrying amount of these securities with limited marketability approximates their fair value.
Deposits and Mortgage Escrow Funds
In accordance with FASB Codification Topic 825, deposits with no stated maturity (such as savings, demand and money market deposits) are assigned fair values equal to the carrying amounts payable on demand. Certificates of deposit and mortgage escrow funds are segregated by account type and original term, and fair values are estimated by discounting the contractual cash flows. The discount rate for each account grouping is equivalent to the current market rates for deposits of similar type and maturity.
These fair values do not include the value of core deposit relationships that comprise a significant portion of the Company’s deposits. We believe that the Company’s core deposit relationships provide a relatively stable, low-cost funding source that has a substantial value separate from the deposit balances.
Borrowings and Senior notes
The estimated fair value approximates carrying value for short-term borrowings. The fair value of long-term fixed-rate borrowings is estimated using quoted market prices, if available, or by discounting future cash flows using current interest rates for similar financial instruments.
Subordinated debentures
The fair value of subordinated debentures is estimated by discounting future cash flows using current interest rates for similar financial instruments.
Other Financial Instruments
Other financial assets and liabilities listed in the table below have estimated fair values that approximate the respective carrying amounts because the instruments are payable on demand or have short-term maturities and present relatively low credit risk and interest rate risk.
The fair values of the Company’s off-balance-sheet financial instruments described in Note 8. Guarantor’s Obligations Under Guarantees were estimated based on current market terms (including interest rates and fees), considering the remaining terms of the agreements and the credit worthiness of the counterparties. At March 31, 2014 and September 30, 2013, the estimated fair value of these instruments approximated the related carrying amounts, which were not material.
Accrued interest receivable/payable
The carrying amounts of accrued interest approximate fair value and are classified as Level 2.

Comprehensive_Income

Comprehensive Income	6 Months Ended
	Mar. 31, 2014
Comprehensive income [Abstract]	'
Comprehensive Income (Loss) Note [Text Block]	'
	Accumulated Other Comprehensive (Loss) Income
	Activity in accumulated other comprehensive (loss) income (“AOCI”), net of tax, for the six month periods ended March 31, 2014 and 2013, was as follows:
		Unrealized gains(losses) on securities				Unrealized gains (losses) for pension and other post-retirement obligations			Total
	Balance at September 30, 2012	$	15,066			$	(8,167	)	$	6,899
	Other comprehensive income before reclassifications	(4,446		)		—			(4,446		)
	Amounts reclassified from AOCI	(2,146		)		612			(1,534		)
	Period change	(6,592		)		612			(5,980		)
	Balance at March 31, 2013	$	8,474			$	(7,555	)	$	919
	Balance at September 30, 2013	$	(11,472	)		$	(3,858	)	$	(15,330	)
	Other comprehensive income before reclassifications	10				—			10
	Amounts reclassified from AOCI	336				699			1,035
	Period change	346				699			1,045
	Balance at March 31, 2014	$	(11,126	)		$	(3,159	)	$	(14,285	)
	The following table presents the reclassification adjustments from AOCI included in net income and the impacted line items on the income statement for the six months ended March 31, 2014:
	Components of AOCI		Amount reclassified from AOCI and impact on net income  (1)				Affected income statement line item
	Unrealized (losses) on available for sale securities:
			$	(585	)		Non-interest income - net loss on sale of securities
			249				Tax benefit
			$	(336	)		Net change after-tax
	Amortization of defined benefit pension items:
	Loss on settlement of portion of defined benefit plan		$	(1,216	)		Non-interest expense - compensation and employee benefits (2)
			517				Tax benefit
			$	(699	)		Net change after-tax
	(1) Amounts in parentheses indicate a reduction from income.
	(2) These accumulated other comprehensive income (loss) components are included in the computation of net periodic pension cost (see Note 13. - Pensions and Other Post Retirement Plans for additional details).

Recent_Accounting_Standards

Recent Accounting Standards	6 Months Ended
	Mar. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
New Accounting Pronouncements, Policy [Policy Text Block]	'
	Recently Issued Accounting Standards Not Yet Adopted
	Accounting Standards Update (“ASU”) 2014-04 - Receivables - Troubled Debt Restructurings by Creditors (Subtopic 310-40) - Reclassification of Residential Real Estate Collateralized Consumer Mortgage loans upon Foreclosure was issued. This standard provides clarification when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan should be removed from the balance sheet and other real estate owned recognized. These amendments clarify that when an in-substance foreclosure occurs, and a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan upon either: (1) the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure, or (2) the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. This standard is effective for annual periods beginning after December 15, 2013 and is not expected to have a material impact on our balance sheet or results of operations.
	ASU 2014-01 - Investments - Equity method and Joint Ventures (Topic 323): Accounting for Investments in qualified Affordable Housing Projects
	was issued. This standard provides reporting guidance for entities that invest in qualified affordable housing projects through limited liability entities that are flow through entities for tax purposes. The amendments in this ASU eliminate the effective yield election and permit the Company to make an accounting policy election to account for its investment in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Under the proportional amortization method, the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the statement of operations as a component of income tax (benefit) expense. The amendments in this ASU should be applied retrospectively to all periods presented. The Company adopted this ASU in the quarter ended March 31, 2014, which coincided with the Company’s initial recognition of low income housing tax credits. The adoption of this ASU resulted in a $400 income tax benefit and a $423 expense associated with the amortization of the Company’s investment for the three month and six month periods ended March 31, 2014. The standard is not expected to have a material impact on our balance sheet or results of operations.

Acquisition_Tables

Acquisition (Tables)	6 Months Ended
	Mar. 31, 2014
Acquisition [Abstract]	'
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	'
	Consideration paid through Sterling Bancorp common stock issued to legacy Sterling shareholders				$	457,759
		Legacy Sterling carrying value				Fair value adjustments				As recorded at acquisition
	Cash and cash equivalents	$	277,798			$	—			$	277,798
	Investment securities	613,154				(5,243		)	(a)	607,911
	Loans held for sale	30,341				—				30,341
	Loans	1,704,801				(6,693		)	(b)	1,698,108
	Federal Reserve Bank stock	7,680				—				7,680
	Bank owned life insurance	55,374				—				55,374
	Premises and equipment	21,293				2,301			(c)	23,594
	Accrued interest receivable	6,590				—				6,590
	Core deposit and other intangibles	—				20,089			(d)	20,089
	Trade name intangible	—				20,500			(e)	20,500
	Other real estate owned	1,720				4,095			(f)	5,815
	Other assets	40,877				(18,326		)	(g)	22,551
	Deposits	(2,296,713		)		(477		)	(h)	(2,297,190		)
	FHLB borrowings	(100,346		)		(273		)	(i)	(100,619		)
	Other borrowings	(62,465		)		—				(62,465		)
	Subordinated debentures	(25,774		)		(753		)	(j)	(26,527		)
	Other liabilities	(60,462		)		4,502			(k)	(55,960		)
	Total identifiable net assets	$	213,868			$	19,722			$	233,590
	Goodwill recorded in the Merger									224,169
	Goodwill at September 30, 2013									163,117
	Goodwill at March 31, 2014									$	387,286
Purchased Credit Impaired Loans	'
	The acquired loan portfolio subject to purchased credit impairment accounting guidance (ASC 310-30) as of October 31, 2013 was comprised of collateral dependent loans with deteriorated credit quality as follows:
		ASC 310-30 loans
	Contractual principal balance at acquisition	$	24,176
	Principal not expected to be collected (non-accretable discount)	(10,927		)
	Expected cash flows at acquisition	13,249
	Interest component of expected cash flows (accretable discount)	—
	Fair value of acquired loans	$	13,249
Business Acquisition, Pro Forma Information	'
		Pro forma for the
		six months ended March 31,
		2014				2013
	Net interest income	$	100,571			$	90,586
	Non-interest income	28,590				34,232
	Non-interest expense	99,368				97,026
	Net income	20,110				19,970
	Pro forma earnings per share:
	Basic	$	0.24			$	0.24
	Diluted	0.24				0.24

Securities_Tables

Securities (Tables)	6 Months Ended
	Mar. 31, 2014
Marketable Securities [Abstract]	'
Summary of securities available for sale	'
	A summary of the amortized cost and estimated fair value of our securities is presented below:
		31-Mar-14												30-Sep-13
		Amortized			Gross			Gross			Fair value			Amortized		Gross			Gross			Fair value
		cost			unrealized			unrealized						cost		unrealized			unrealized
					gains			losses								gains			losses
	Available for Sale
	Residential mortgage-backed securities (“MBS”):
	Agency-backed	$	458,121		$	1,925		$	(2,531	)	$	457,515		$	284,837	$	1,849		$	(4,157	)	$	282,529
	CMO/Other MBS	136,304			235			(1,688		)	134,851			169,336		356			(3,038		)	166,654
	Total residential MBS	594,425			2,160			(4,219		)	592,366			454,173		2,205			(7,195		)	449,183
	Other securities:
	Federal agencies	217,942			3			(8,244		)	209,701			273,637		—			(12,090		)	261,547
	Corporate	225,628			180			(3,610		)	222,198			118,575		153			(3,795		)	114,933
	State and municipal	134,881			3,038			(783		)	137,136			127,324		3,447			(2,041		)	128,730
	Trust preferred	65,277			1,809			—			67,086			—		—			—			—
	Mutual funds	4,874			—			(51		)	4,823			—		—			—			—
	Total other securities	648,602			5,030			(12,688		)	640,944			519,536		3,600			(17,926		)	505,210
	Total available for sale	$	1,243,027		$	7,190		$	(16,907	)	$	1,233,310		$	973,709	$	5,805		$	(25,121	)	$	954,393
Held-to-maturity securities	'
		31-Mar-14												30-Sep-13
		Amortized			Gross			Gross			Fair value			Amortized		Gross			Gross			Fair value
		cost			unrecognized			unrecognized						cost		unrecognized			unrecognized
					gains			losses								gains			losses
	Held to Maturity
	Residential MBS:
	Agency-backed	$	128,212		$	691		$	(362	)	$	128,541		$	130,371	$	716		$	(108	)	$	130,979
	CMO/Other MBS	67,982			13			(1,859		)	66,136			25,776		33			(315		)	25,494
	Total residential MBS	196,194			704			(2,221		)	194,677			156,147		749			(423		)	156,473
	Other securities:
	Federal agencies	135,998			740			(1,375		)	135,363			77,341		—			(3,458		)	73,883
	State and municipal	193,573			2,300			(312		)	195,561			19,011		556			(546		)	19,021
	Other	1,500			20			—			1,520			1,500		19			—			1,519
	Total other securities	331,071			3,060			(1,687		)	332,444			97,852		575			(4,004		)	94,423
	Total held to maturity	$	527,265		$	3,764		$	(3,908	)	$	527,121		$	253,999	$	1,324		$	(4,427	)	$	250,896
Investments Classified by Contractual Maturity Date [Table Text Block]	'
	The amortized cost and estimated fair values of securities at March 31, 2014 are presented below by contractual maturity. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Residential mortgage-backed securities are shown separately since they are not due at a single maturity date.
		March 31, 2014
		Available for sale						Held to maturity
		Amortized			Fair			Amortized			Fair
		cost			value			cost			value
	Remaining period to contractual maturity:
	One year or less	$	27,970		$	27,977		$	8,790		$	8,874
	One to five years	180,125			179,888			5,110			5,356
	Five to ten years	367,390			358,028			149,874			149,293
	Greater than ten years	73,117			75,051			167,297			168,921
	Total other securities	648,602			640,944			331,071			332,444
	Residential MBS	594,425			592,366			196,194			194,677
	Total securities	$	1,243,027		$	1,233,310		$	527,265		$	527,121
Sale of Securities [Table Text Block]	'
	Sales of securities for the three and six months ended March 31, 2014 and 2013 were as follows:
		For the three months ended March 31,						For the six months ended March 31,
		2014			2013			2014			2013
	Available for sale securities:
	Proceeds from sales	$	55,778		$	94,839		$	305,489		$	136,804
	Gross realized gains	65			2,202			276			3,618
	Gross realized losses	(5		)	(10		)	(861		)	(10		)
	Income tax (expense) benefit on realized gains (losses)	(18		)	(552		)	229			(1,010		)
	Held to maturity securities:
	Proceeds from sales	—			1,234			—			1,234
	Gross realized gains	—			37			—			37
	Income tax expense on realized gains	—			(9		)	—			(10		)
Securities available for sale with unrealized losses	'
	The following table summarizes securities with unrealized losses, segregated by the length of time in a continuous unrealized loss position:
		Continuous unrealized loss position
		Less than 12 Months						12 months or longer						Total
		Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
		value			losses			value			losses			value		losses
	Available for Sale
	31-Mar-14
	Residential MBS:
	Agency-backed	$	179,009		$	(691	)	$	67,082		$	(1,840	)	$	246,091	$	(2,531	)
	CMO/Other MBS	64,069			(676		)	27,175			(1,012		)	91,244		(1,688		)
	Total residential MBS	243,078			(1,367		)	94,257			(2,852		)	337,335		(4,219		)
	Federal agencies	51,116			(2,048		)	158,091			(6,196		)	209,207		(8,244		)
	Corporate	86,663			(925		)	90,763			(2,685		)	177,426		(3,610		)
	State and municipal	28,293			(252		)	16,308			(531		)	44,601		(783		)
	Mutual fund	4,827			(51		)	—			—			4,827		(51		)
	Total	$	413,977		$	(4,643	)	$	359,419		$	(12,264	)	$	773,396	$	(16,907	)
	30-Sep-13
	Residential MBS:
	Agency-backed	$	137,265		$	(4,157	)	$	—		$	—		$	137,265	$	(4,157	)
	CMO/Other MBS	122,324			(2,742		)	7,820			(296		)	130,144		(3,038		)
	Total residential MBS	259,589			(6,899		)	7,820			(296		)	267,409		(7,195		)
	Federal agencies	261,547			(12,090		)	—			—			261,547		(12,090		)
	Corporate	95,013			(3,795		)	—			—			95,013		(3,795		)
	State and municipal	43,585			(2,033		)	112			(8		)	43,697		(2,041		)
	Total	$	659,734		$	(24,817	)	$	7,932		$	(304	)	$	667,666	$	(25,121	)
Securities held to maturity with unrealized losses	'
		Continuous unrealized loss position
		Less than 12 Months						12 Months or longer						Total
		Fair			Unrealized			Fair			Unrealized			Fair		Unrealized
		value			losses			value			losses			value		losses
	Held to Maturity
	March 31, 2014
	Residential MBS:
	Agency-backed	$	61,535		$	(362	)	$	—		$	—		$	61,535	$	(362	)
	CMO/Other MBS	61,924			(1,859		)	—			—			61,924		(1,859		)
	Total residential MBS	123,459			(2,221		)	—			—			123,459		(2,221		)
	Federal agencies	40,085			(1,375		)	—			—			40,085		(1,375		)
	State and municipal	29,723			(1,312		)	—			—			29,723		(312		)
	Total	$	193,267		$	(3,908	)	$	—		$	—		$	193,267	$	(3,908	)
	30-Sep-13
	Residential MBS:
	Agency-backed	$	10,963		$	(86	)	$	—		$	—		$	10,963	$	(86	)
	CMO/Other MBS	31,412			(337		)	—			—			31,412		(337		)
	Total residential MBS	42,375			(423		)	—			—			42,375		(423		)
	Federal agencies	73,883			(3,458		)	—			—			73,883		(3,458		)
	State and municipal	9,530			(546		)	—			—			9,530		(546		)
	Total	$	125,788		$	(4,427	)	$	—		$	—		$	125,788	$	(4,427	)
Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block]	'
	Securities pledged for borrowings at FHLB and other institutions, and securities pledged for municipal deposits and other purposes were as follows:
		March 31, 2014			September 30, 2013
	Available for sale securities pledged for borrowings, at fair value	$	268,017		$	199,642
	Available for sale securities pledged for municipal deposits, at fair value	505,185			580,756
	Held to maturity securities pledged for back-to-back swaps, at amortized cost	5,037			4,645
	Held to maturity securities pledged for borrowings, at amortized cost	71,393			55,497
	Held to maturity securities pledged for municipal deposits, at amortized cost	322,666			167,926
	Total securities pledged	$	1,172,298		$	1,008,466

Loans_Tables

Loans (Tables)	6 Months Ended
	Mar. 31, 2014
Loans [Abstract]	'
Components of loan portfolio excluding loans held for sale	'
	The composition of the Company’s loan portfolio, excluding loans held for sale, was the following:
		March 31, 2014				September 30, 2013
	Commercial:
	Commercial & industrial	$	1,072,203			$	439,787
	Payroll finance	126,830				—
	Warehouse lending	150,280				—
	Factored receivables	145,979				—
	Equipment financing	332,082				—
	Total commercial	1,827,374				439,787
	Commercial mortgage:
	Commercial real estate	1,315,220				969,490
	Multi-family	298,782				307,547
	Acquisition, development & construction	90,905				102,494
	Total commercial mortgage	1,704,907				1,379,531
	Total commercial and commercial mortgage	3,532,281				1,819,318
	Residential mortgage	512,875				400,009
	Consumer:
	Home equity lines of credit	152,820				156,995
	Other consumer loans	46,378				36,576
	Total consumer	199,198				193,571
	Total loans	4,244,354				2,412,898
	Allowance for loan losses	(32,015		)		(28,877		)
	Total loans, net	$	4,212,339			$	2,384,021
Troubled debt restructurings and other real estate owned	'
	The following tables set forth the amounts and status of the Company’s loans and troubled debt restructurings (“TDRs”) at March 31, 2014 and September 30, 2013:
		March 31, 2014
		Current				30-59				60-89			90+			Non-			Total
						days				days			days			accrual
						past due				past due			past due
	Commercial & industrial	$	1,068,821			$	617			$	355		$	7		$	2,403		$	1,072,203
	Payroll finance	84,950				31,324				7,351			3,205			—			126,830
	Warehouse lending	150,280				—				—			—			—			150,280
	Factored receivables	135,834				4,620				2,628			1,905			992			145,979
	Equipment financing	330,559				1,077				170			—			276			332,082
	Commercial real estate	1,289,316				1,389				7,737			—			16,778			1,315,220
	Multi-family	298,782				—				—			—			—			298,782
	Acquisition, development & construction	75,115				272				737			—			14,781			90,905
	Residential mortgage	494,438				2,175				1,063			273			14,926			512,875
	Consumer	192,256				1,289				928			4			4,721			199,198
	Total loans	$	4,120,351			$	42,763			$	20,969		$	5,394		$	54,877		$	4,244,354
	Total TDRs included above	$	14,502			$	1,241			$	2,232		$	—		$	12,116		$	30,091
	Non-performing loans:
	Loans 90+ days past due and still accruing															$	5,394
	Non-accrual loans															54,877
	Total non-performing loans															$	60,271
		September 30, 2013
		Current				30-59				60-89			90+			Non-			Total
						days				days			days			accrual
						past due				past due			past due
	Commercial & industrial	$	438,818			$	178			$	2		$	289		$	500		$	439,787
	Commercial real estate	1,263,933				1,978				2,357			1,574			7,195			1,277,037
	Acquisition, development & construction	96,306				768				—			—			5,420			102,494
	Residential mortgage	390,072				354				267			1,832			7,484			400,009
	Consumer	190,393				566				—			404			2,208			193,571
	Total loans	$	2,379,522			$	3,844			$	2,626		$	4,099		$	22,807		$	2,412,898
	Total TDRs included above	$	23,754			$	—			$	—		$	141		$	2,199		$	26,094
	Non-performing loans:
	Loans 90+ days past due and still accruing															$	4,099
	Non-accrual loans															22,807
	Total non-performing loans															$	26,906
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'
	Activity in the allowance for loan losses for the three and six months ended March 31, 2014 and 2013 is summarized below:
		For the three months ended March 31, 2014
		Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
		balance											charge-offs
	Commercial & industrial	$	6,886			$	(1,164	)		$	74		$	(1,090	)	$	873		$	6,669
	Payroll finance	—				—				—			—			610			610
	Warehouse lending	—				—				—			—			132			132
	Factored receivables	—				(289		)		—			(289		)	668			379
	Equipment financing	—				(167		)		—			(167		)	1,473			1,306
	Commercial real estate	9,992				(280		)		19			(261		)	1,135			10,866
	Acquisition, development & construction	5,857				(1,260		)		—			(1,260		)	(1,038		)	3,559
	Residential mortgage	4,600				(148		)		1			(147		)	112			4,565
	Consumer	3,277				(204		)		21			(183		)	835			3,929
	Total loans	$	30,612			$	(3,512	)		$	115		$	(3,397	)	$	4,800		$	32,015
	Annualized net charge-offs to average loans outstanding																		0.34		%
	Loans acquired from Gotham Bank and legacy Sterling with a carrying amount of $1,378,608 were not included in the Company’s allowance for loan losses at March 31, 2014 as such loans include a fair value discount that considers expected lifetime credit losses.
		For the three months ended March 31, 2013
		Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
		balance											charge-offs
	Commercial & industrial	$	5,533			$	(359	)		$	127		$	(232	)	$	(930	)	$	4,371
	Commercial real estate	7,616				(1,199		)		331			(868		)	2,401			9,149
	Acquisition, development & construction	7,026				(567		)		164			(403		)	(521		)	6,102
	Residential mortgage	4,368				(959		)		9			(950		)	1,025			4,443
	Consumer	3,571				(748		)		31			(717		)	625			3,479
	Total loans	$	28,114			$	(3,832	)		$	662		$	(3,170	)	$	2,600		$	27,544
	Annualized net charge-offs to average loans outstanding																		0.58		%
		For the six months ended March 31, 2014
		Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
		balance											charge-offs
	Commercial & industrial	$	5,302			$	(1,692	)		$	575		$	(1,117	)	$	2,484		$	6,669
	Payroll finance	—				—				—			—			610			610
	Warehouse lending	—				—				—			—			132			132
	Factored receivables	—				(289		)		—			(289		)	668			379
	Equipment financing	—				(167		)		—			(167		)	1,473			1,306
	Commercial real estate	9,967				(951		)		56			(895		)	1,794			10,866
	Acquisition, development & construction	5,806				(1,478		)		—			(1,478		)	(769		)	3,559
	Residential mortgage	4,474				(418		)		8			(410		)	501			4,565
	Consumer	3,328				(351		)		45			(306		)	907			3,929
	Total loans	$	28,877			$	(5,346	)		$	684		$	(4,662	)	$	7,800		$	32,015
	Annualized net charge-offs to average loans outstanding																		0.25		%
		For the six months ended March 31, 2013
		Beginning				Charge-offs				Recoveries			Net			Provision			Ending balance
		balance											charge-offs
	Commercial & industrial	$	4,603			$	(518	)		$	247		$	(271	)	$	39		$	4,371
	Commercial real estate	7,230				(1,427		)		412			(1,015		)	2,934			9,149
	Acquisition, development & construction	8,526				(2,161		)		169			(1,992		)	(432		)	6,102
	Residential mortgage	4,359				(1,909		)		60			(1,849		)	1,933			4,443
	Consumer	3,564				(1,231		)		70			(1,161		)	1,076			3,479
	Total loans	$	28,282			$	(7,246	)		$	958		$	(6,288	)	$	5,550		$	27,544
	Annualized net charge-offs to average loans outstanding																		0.58		%
	Management considers a loan to be impaired when, based on current information and events, it is determined that the Company will not be able to collect all amounts due according to the loan contract, including scheduled interest payments. Determination of impairment is treated the same across all classes of loans on a loan-by-loan basis, except residential mortgage loans and home equity lines of credit with an outstanding balance of $500 or less which are evaluated for impairment on a homogeneous pool basis. When management identifies a loan as impaired, the impairment is measured based on the present value of expected future cash flows, discounted at the loan’s effective interest rate, except when the sole remaining source of repayment of the loan is the operation or liquidation of the collateral. In these cases, management uses the current fair value of the collateral, less selling costs when foreclosure is probable, instead of discounted cash flows. If management determines that the value of the impaired loan is less than the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount), impairment is generally recognized through a charge-off to the allowance for loan losses.
	When the ultimate collectibility of the total principal of an impaired loan is in doubt and the loan is on non-accrual status, all payments are applied to principal, under the cost recovery method. When the ultimate collectibility of the total principal of an impaired loan is not in doubt and the loan is on non-accrual status, contractual interest is credited to interest income when received, under the cash basis method.
Loans Evaluated For Impairment By Segment	'
	The following table presents loans individually evaluated for impairment by segment of loans at March 31, 2014 and September 30, 2013:
		31-Mar-14											30-Sep-13
		Unpaid				Recorded				Related allowance			Unpaid			Recorded			Related allowance
		principal				investment							principal			investment
		balance											balance
	With no related allowance recorded:
	Commercial & industrial	$	1,841			$	1,841			$	—		$	2,175		$	2,131		$	—
	Factored receivables	992				992				—			—			—			—
	Commercial real estate	12,847				12,732				—			12,451			11,820			—
	Acquisition, development & construction	21,915				21,005				—			17,971			17,945			—
	Residential mortgage	515				515				—			515			515			—
	Subtotal	38,110				37,085				—			33,112			32,411			—
	With an allowance recorded:
	Commercial & industrial	—				—				—			500			500			249
	Commercial real estate	—				—				—			3,150			2,271			803
	Acquisition, development & construction	—				—				—			2,753			1,637			540
	Consumer	—				—				—			2			2			1
	Subtotal	—				—				—			6,405			4,410			1,593
	Total	$	38,110			$	37,085			$	—		$	39,517		$	36,821		$	1,593
	During the quarter ended March 31, 2014, the Company modified its allowance for loan loss policy to generally require the charge-off of loan amounts identified as impaired.
	The following table presents the average recorded investment and interest income recognized related to loans individually evaluated for impairment by segment for the three and six months ended March 31, 2014 and 2013:
		For the three months ended March 31, 2014											For the three months ended March 31, 2013
		QTD				Interest				Cash-basis			QTD			Interest			Cash-basis
		average				income				interest			average			income			interest
		recorded				recognized				income			recorded			recognized			income
		investment								recognized			investment						recognized
	With no related allowance recorded:
	Commercial & industrial	$	1,850			$	—			$	—		$	1,873		$	45		$	21
	Factored receivables	992				—				—			—			—			—
	Commercial real estate	12,512				40				—			9,248			99			53
	Multi-family	264				—				—			—			—			—
	Acquisition, development & construction	21,940				66				—			15,582			313			161
	Residential mortgage	515				—				—			7,978			100			52
	Consumer	—				—				—			2,127			7			3
	Subtotal	38,073				106				—			36,808			564			290
	With an allowance recorded:
	Commercial & industrial	—				—				—			368			3			3
	Commercial real estate	—				—				—			6,265			13			9
	Residential mortgage	—				—				—			3,857			14			6
	Acquisition, development & construction	—				—				—			649			—			—
	Consumer	—				—				—			700			4			2
	Subtotal	—				—				—			11,839			34			20
	Total	$	38,073			$	106			$	—		$	48,647		$	598		$	310
Loans and allowance evaluated for impairment by segment	'
	The following table sets forth loans evaluated for impairment by segment and the allowance evaluated by segment at March 31, 2014:
		Loans evaluated by segment														Allowance evaluated by segment
		Individually				Collectively				Purchased credit impaired loans			Total			Individually			Collectively			Total allowance for loan losses
		evaluated for				evaluated for							loans			evaluated for			evaluated for
		impairment				impairment										impairment			impairment
	Commercial & industrial	$	1,841			$	1,068,031			$	2,331		$	1,072,203		$	—		$	6,669		$	6,669
	Payroll finance	—				126,830				—			126,830			—			610			610
	Warehouse lending	—				150,280				—			150,280			—			132			132
	Factored receivables	992				144,987				—			145,979			—			379			379
	Equipment financing	—				332,082				—			332,082			—			1,306			1,306
	Commercial real estate	12,732				1,594,397				6,873			1,614,002			—			10,866			10,866
	Acquisition, development & construction	21,005				69,900				—			90,905			—			3,559			3,559
	Residential mortgage	515				508,932				3,428			512,875			—			4,565			4,565
	Consumer	—				199,198				—			199,198			—			3,929			3,929
	Total loans	$	37,085			$	4,194,637			$	12,632		$	4,244,354		$	—		$	32,015		$	32,015
	There was no amount included in the allowance for loan losses associated with purchased credit impaired loans at March 31, 2014, as there was no further deterioration in the credit quality of these loans since the Merger date.
	The following table sets forth the loans evaluated for impairment by segment and the allowance evaluated by segment at September 30, 2013:
		Loans evaluated by segment											Allowance evaluated by segment
		Individually				Collectively				Total			Individually			Collectively			Total allowance for loan losses
		evaluated for				evaluated for				loans			evaluated for			evaluated for
		impairment				impairment							impairment			impairment
	Commercial & industrial	$	2,631			$	437,156			$	439,787		$	249		$	5,053		$	5,302
	Commercial real estate & multi-family	14,091				1,262,946				1,277,037			803			9,164			9,967
	Acquisition, development & construction	19,582				82,912				102,494			540			5,266			5,806
	Residential mortgage	515				399,494				400,009			—			4,474			4,474
	Consumer	2				193,569				193,571			1			3,327			3,328
	Total loans	$	36,821			$	2,376,077			$	2,412,898		$	1,593		$	27,284		$	28,877
Troubled debt restructurings	'
	The following table presents loans by segment modified as TDRs that occurred during the three months ended March 31, 2014 and 2013:
		March 31, 2014										31-Mar-13
					Recorded investment									Recorded investment
		Number			Pre-				Post-			Number		Pre-			Post-
					modification				modification					modification			modification
	Commercial & industrial	—			$	—			$	—		2		$	169		$	169
	Acquisition, development & construction	2			1,060				1,060			5		3,049			3,049
	Total restructured loans	2			$	1,060			$	1,060		7		$	3,218		$	3,218
	The following table presents loans by segment modified as TDRs that occurred during the six months ended March 31, 2014 and 2013:
		March 31, 2014										31-Mar-13
					Recorded investment									Recorded investment
		Number			Pre-				Post-			Number		Pre-			Post-
					modification				modification					modification			modification
	Commercial & industrial	—			$	—			$	—		3		$	1,669		$	1,669
	Commercial real estate & multi-family	—			—				—			1		450			450
	Acquisition, development & construction	2			1,060				1,060			7		5,772			5,772
	Residential mortgage	—			—				—			1		275			275
	Total restructured loans	2			$	1,060			$	1,060		12		$	8,166		$	8,166
	The following tables set forth the amounts of the Company’s TDRs at March 31, 2014 and September 30, 2013:
		31-Mar-14
		Current loans				30-59				60-89			90+			Non-			Total
						days				days			days			accrual
						past due				past due			past due
	Commercial & industrial	$	307			$	—			$	—		$	—		$	1,623		$	1,930
	Commercial real estate	2,613				—				2,232			—			448			5,293
	Acquisition, development & construction	6,090				272				—			—			6,956			13,318
	Residential mortgage	5,492				969				—			—			2,868			9,329
	Consumer	—				—				—			—			221			221
	Total	$	14,502			$	1,241			$	2,232		$	—		$	12,116		$	30,091
	Allowance for loan losses	$	52			$	—			$	—		$	—		$	14		$	66
		30-Sep-13
		Current loans				30-59				60-89			90+			Non-			Total
						days				days			days			accrual
						past due				past due			past due
	Commercial & industrial	$	1,843			$	—			$	—		$	141		$	—		$	1,984
	Commercial real estate	5,305				—				—			—			—			5,305
	Acquisition, development & construction	14,190				—				—			—			151			14,341
	Residential mortgage	2,416				—				—			—			1,792			4,208
	Consumer	—				—				—			—			256			256
	Total	$	23,754			$	—			$	—		$	141		$	2,199		$	26,094
	Allowance for loan losses	$	438			$	—			$	—		$	—		$	439		$	877
Risk category of loans by segment of gross loans	'
		March 31, 2014											September 30, 2013
		Special				Substandard				Doubtful			Special			Substandard			Doubtful
		mention											mention
	Commercial & industrial	$	25,620			$	7,731			$	2		$	3,545		$	3,855		$	365
	Factored receivables	1,743				992				—			—			—			—
	Equipment financing	—				276				—			—			—			—
	Commercial real estate	8,813				33,627				—			7,279			24,561			227
	Multi-family	—				617				—			—			—			—
	Acquisition, development & construction	1,060				18,555				—			1,867			19,410			—
	Residential mortgage	1,805				15,732				—			824			9,786			—
	Consumer	923				5,141				—			15			2,891			—
	Total	$	39,964			$	82,671			$	2		$	13,530		$	60,503		$	592

Deposits_Tables

Deposits (Tables)	6 Months Ended
	Mar. 31, 2014
Deposits [Abstract]	'
Summary of major classification of deposits	'
	Deposit balances are summarized as follows:
		March 31,		September 30,
		2014		2013
	Non-interest bearing demand	$	1,687,775	$	943,934
	Interest bearing demand	744,701		434,398
	Savings	607,601		580,125
	Money market	1,637,838		735,709
	Certificates of deposit	533,809		268,128
	Total deposits	$	5,211,724	$	2,962,294
List of Company's Brokered deposits	'
	Summarized below are the Company’s brokered deposits included in the table above:
		March 31,		September 30,
		2014		2013
	Money market	$	59,131	$	34,571
	Reciprocal CDARs(1)	33,243		1,343
	CDARs one way	3,257		768
	Total brokered deposits	$	95,631	$	36,682
	(1)  Certificate of deposit account registry service.

Borrowings_Tables

Borrowings (Tables)	6 Months Ended
	Mar. 31, 2014
Debt Instruments [Abstract]	'
Schedule of debt	'
	The Company’s FHLB and other borrowings and weighted average interest rates are summarized below:
		March 31, 2014				September 30, 2013
		Amount		Rate		Amount		Rate
	By type of borrowing:
	FHLB borrowings	$	489,801	2.34	%	$	442,602	2.77	%
	Repurchase agreements	19,991		0.36		20,351		0.88
	Senior Notes	98,215		5.98		98,033		5.98
	Total borrowings	$	608,007	2.86	%	$	560,986	3.26	%
	By remaining period to maturity:
	One year or less	$	109,328	1.01	%	$	158,897	0.95	%
	One to two years	145,224		0.56		78,717		1.97
	Two to three years	132,614		3.43		191		5.32
	Three to four years	120,000		4.1		202,414		4.21
	Four to five years	98,215		5.98		118,033		5.57
	Greater than five years	2,626		4.92		2,734		4.92
	Total borrowings	$	608,007	2.86	%	$	560,986	3.26	%

Subordinated_Debentures_Tables

Subordinated Debentures (Tables)	6 Months Ended
	Mar. 31, 2014
Subordinated Debentures [Abstract]	'
Schedule of Subordinated Borrowing [Table Text Block]	'
		March 31, 2014		September 30, 2013
	Subordinated debentures	$	25,774	$	—
	Premium recorded to reflect fair value at acquisition date	735		—
		$	26,509	$	—

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	6 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Computation of basic and diluted earnings per share	'
	Basic earnings per common share are computed as follows:
		For the three months ended March 31,				For the six months ended March 31,
		2014		2013		2014			2013
	Weighted average common shares outstanding (basic)	83,497,765		43,743,640		76,924,082			43,704,163
	Net income (loss)	$	10,332	$	6,529	$	(3,671	)	$	13,549
	Basic earnings (loss) per common share	0.12		0.15		(0.05		)	0.31
	Diluted earnings per common share are computed as follows:
		For the three months ended March 31,				For the six months ended March 31,
		2014		2013		2014			2013
	Weighted average common shares outstanding (basic)	83,497,765		43,743,640		76,924,082			43,704,163
	Effect of common stock equivalents	296,342		104,846		—			86,752
	Weighted average common shares outstanding (diluted)	83,794,107		43,848,486		76,924,082			43,790,915
	Net income (loss)	$	10,332	$	6,529	$	(3,671	)	$	13,549
	Diluted earnings (loss) per common share	0.12		0.15		(0.05		)	0.31

Other_Noninterest_expense_Tabl

Other Non-interest expense (Tables)	6 Months Ended
	Mar. 31, 2014
Other Non-Interest Expense [Abstract]	'
Other non- interest expense [Table Text Block]	'
		For the three months ended March 31,				For the six months ended March 31,
		2014		2013		2014		2013
	Other non-interest expense:
	Advertising and promotion	$	422	$	535	731		779
	Professional fees	1,500		912		3,319		2,128
	Data and check processing	663		823		1,258		1,471
	Insurance - general	637		213		1,217		468
	Other	4,852		1,820		9,426		4,130
	Total other non-interest expense	$	8,074	$	4,303	$	15,951	$	8,976

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Fair value of options granted determined using weighted-average assumptions as grant date	'
	The fair value of options granted was determined using the following weighted average assumptions as of the grant date:
		For the six months ended March 31,
		2014		2013
	Risk-free interest rate	1.74	%	0.96	%
	Expected stock price volatility	26.5	%	40.8	%
	Dividend yield (1)	2.05	%	2.61	%
	Expected term in years	5.75		5.75
	(1) Represents the approximate annualized cash dividend rate paid with respect to a share of common stock at or near the grant date.
Summary of Company's stock option activity	'
	The following table summarizes the combined activity in the Company’s stock-based compensation plans for the six months ended March 31, 2014:
				Non-vested stock awards/stock units outstanding				Stock options outstanding
		Shares available for grant		Number of shares		Weighted average grant date fair value		Number of shares		Weighted average exercise price
	Balance at September 30, 2013	2,066,184		209,697		$	8.73	2,114,509		$	10.71
	2014 Stock Incentive Plan	3,400,000		—		—		—		—
	Grants associated with the Merger(1)	(921,503	)	351,964		11.72		104,152		14.25
	Granted (1)	(595,435	)	101,078		11.36		249,862		11.36
	Stock awards vested	—		(46,590	)	8.75		—		—
	Exercised	—		—		—		(432,056	)	11.79
	Forfeited	331,694		(15,996	)	8.86		(274,109	)	12.08
	Canceled/expired	(5,000	)	—		—		—		—
	Balance at March 31, 2014	4,275,940		600,153		$	10.89	1,762,358		$	10.53
	Exercisable at March 31, 2014							1,058,882		$	11.24
	(1) Reflects certain non-vested stock awards that count as 3.5 shares deducted from the plan for every one share delivered under these awards.

Pension_and_Other_Post_Retirem1

Pension and Other Post Retirement Plans (Tables)	6 Months Ended
	Mar. 31, 2014
Compensation Related Costs [Abstract]	'
Net post-retirement cost, recorded within salaries and employee benefits expense	'
	Net pension expense for the three months and six months ended March 31, 2014 was incurred for the Provident Bank Benefit Pension Plan (the “legacy Provident Plan”) and legacy Sterling/Sterling National Bank employees’ Retirement Plan (the “legacy Sterling Plan”). Net pension expense and and post-retirement expense, which is recorded in compensation and employee benefits expense in the consolidated statements of operations, is comprised of the following:
		Pension plan						Other post
								retirement plans
		For the three months ended March 31,						For the three months ended March 31,
		2014			2013			2014		2013
	Service cost	$	—		$	—		$	—	$	11
	Interest cost	1,377			363			11		31
	Expected return on plan assets	(1,701		)	(615		)	32		—
	Amortization of net transition obligation	—			—			6		6
	Amortization of prior service cost	—			—			12		12
	Amortization of (gain) or loss	48			515			—		(6		)
	Charge for settlement of a portion of defined benefit plan	1,352			—			—		—
	Total cost	$	1,076		$	263		$	61	$	54
		Pension plan						Other post
								retirement plans
		For the six months ended March 31,						For the six months ended March 31,
		2014			2013			2014		2013
	Service cost	$	—		$	—		$	—	$	23
	Interest cost	1,779			726			23		63
	Expected return on plan assets	(2,372		)	(1,231		)	66		—
	Amortization of net transition obligation	—			—			12		12
	Amortization of prior service cost	—			—			24		23
	Amortization of (gain) or loss	145			1,031			—		(13		)
	Charge for settlement of a portion of defined benefit plan	4,095			—			—		—
	Total cost	$	3,647		$	526		$	125	$	108

Derivatives_Tables

Derivatives (Tables)	6 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedges, Assets [Abstract]	'
Summary of derivatives	'
	Summary information regarding these derivatives is presented below:
		Notional			Average	Weighted		Weighted average	Fair value
		amount			maturity (in years)	average		variable rate
						fixed rate
	At March 31, 2014
	Interest rate caps	$	50,000		0.68	3.75	%	NA	$	—
	Third-party interest rate swaps	53,141			5.26	4.22		1 m Libor + 2.45	756
	Customer interest rate swaps	(53,141		)	5.26	4.22		1 m Libor + 2.45	(756		)
	At September 30, 2013
	Interest rate caps	$	50,000		1.18	3.75	%	NA	$	—
	Third-party interest rate swaps	54,180			5.76	4.22		1 m Libor + 2.45	997
	Customer interest rate swaps	(54,180		)	5.76	4.22		1 m Libor + 2.45	(997		)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Estimated fair value on a recurring basis	'
	A summary of assets and liabilities at September 30, 2013 measured at estimated fair value on a recurring basis is as follows:
		September 30, 2013
		Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
	Assets:
	Investment securities available for sale:
	Residential mortgage-backed securities:
	Agency-backed	$	282,529		$	—			$	282,529		$	—
	CMO/Other MBS	163,041			—				163,041			—
	Private label CMOs	3,613			—				—			3,613
	Total residential mortgage-backed securities	449,183			—				445,570			3,613
	Other securities:
	Federal agencies	261,547			—				261,547			—
	Corporate bonds	114,933			—				114,933			—
	State and municipal	128,730			—				128,730			—
	Total other securities	505,210			—				505,210			—
	Total investment securities available for sale	954,393			—				950,780			3,613
	Interest rate caps and swaps	997			—				997			—
	Total assets measured at estimated fair value on a recurring basis	$	955,390		$	—			$	951,777		$	3,613
	Liabilities:
	Interest rate swaps	$	997		$	—			$	997		$	—
	Total liabilities measured at estimated fair value on a recurring basis	$	997		$	—			$	997		$	—
	A summary of assets and liabilities at March 31, 2014 measured at estimated fair value on a recurring basis is as follows:
		March 31, 2014
		Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
	Assets:
	Investment securities available for sale:
	Residential mortgage-backed securities:
	Agency-backed	$	457,515		$	—			$	457,515		$	—
	CMO/Other MBS	131,621			—				131,621			—
	Private label CMOs	3,230			—				—			3,230
	Total residential mortgage-backed securities	592,366			—				589,136			3,230
	Other securities:
	US Government	—			—				—			—
	Federal agencies	209,701			—				209,701			—
	Corporate bonds	222,198			—				222,198			—
	State and municipal	137,136			—				137,136			—
	Trust preferred	67,086			—				67,086			—
	Mutual funds	4,823			—				4,823			—
	Total other securities	640,944			—				640,944			—
	Total investment securities available for sale	1,233,310			—				1,230,080			3,230
	Interest rate caps and swaps	756			—				756			—
	Total assets measured at estimated fair value on a recurring basis	$	1,234,066		$	—			$	1,230,836		$	3,230
	Liabilities:
	Interest rate swaps	$	756		$	—			$	756		$	—
	Total liabilities measured at estimated fair value on a recurring basis	$	756		$	—			$	756		$	—
Impaired loans measured at estimated fair value on nonrecurring basis	'
	March 31, 2014 measured at estimated fair value on a non-recurring basis is the following:
		March 31, 2014
		Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
	Commercial real estate	897			—				—			897
	Acquisition, development & construction	2,462			—				—			2,462
	Total impaired loans measured at fair value	$	3,359		$	—			$	—		$	3,359
	A summary of impaired loans at September 30, 2013 measured at estimated fair value on a non-recurring basis is the following:
		September 30, 2013
		Fair value			Level 1 inputs				Level 2 inputs			Level 3 inputs
	Commercial & industrial	$	500		$	—			$	—		$	500
	Commercial real estate	3,672			—				—			3,672
	Acquisition, development & construction	1,839			—				—			1,839
	Consumer	2			—				—			2
	Total impaired loans measured at fair value	$	6,013		$	—			$	—		$	6,013
Quantitative information of Level 3 assets	'
	March 31, 2014:
	Non-recurring fair value measurements		Fair value			Valuation technique		Unobservable input / assumptions		Range(1) (weighted average)
	Impaired loans:
	Commercial real estate and multi-family		$	897		Appraisal		Adjustments for comparable properties		15.0% - 36.0% (22.0%)
	Acquisition, development & construction		2,462			Appraisal		Adjustments for comparable properties		10.0% - 30.0% (13.5%)
	Assets taken in foreclosure:
	Commercial real estate		8,388			Appraisal		Adjustments by management to reflect current conditions/selling costs		20.0% - 37.0% (24.8%)
	Residential mortgage		887			Appraisal		Adjustments by management to reflect current conditions/selling costs		16.0% - 59.0% (21.6%)
	Mortgage servicing rights		1,747			Third-party valuation		Discount rate		9.3% - 12.8%
						Third-party valuation		Prepayment speed		100 - 968 (weighted average of 224)
Summary of carrying amounts and estimated fair values of financial assets and liabilities	'
	The following is a summary of the carrying amounts and estimated fair values of financial assets and liabilities (none of which were held for trading purposes) as of March 31, 2014:
		March 31, 2014
		Carrying			Level 1 inputs				Level 2 inputs			Level 3 inputs
		amount
	Financial assets:
	Cash and due from banks	$	164,645		$	164,645			$	—		$	—
	Securities available for sale	1,233,310			—				1,230,080			3,230
	Securities held to maturity	527,265			—				527,121			—
	Loans, net	4,212,339			—				—			4,254,200
	Loans held for sale	21,348			—				21,348			—
	Accrued interest receivable on securities	8,810			—				8,810			—
	Accrued interest receivable on loans	9,344			—				—			9,344
	FHLB stock and Federal Reserve Bank stock	53,346			—				—			—
	Interest rate caps and swaps	756			—				756			—
	Financial liabilities:
	Non-maturity deposits	$	(4,677,915	)	$	(4,677,915	)		$	—		$	—
	Certificates of deposit	(533,809		)	—				(533,733		)	—
	FHLB and other borrowings	(489,801		)	—				(511,976		)	—
	Other borrowings	(19,991		)	—				(19,992		)	—
	Senior Notes	(98,215		)	—				(100,947		)	—
	Subordinated debentures	(26,509		)	—				(26,149		)	—
	Mortgage escrow funds	(8,711		)	—				(8,710		)	—
	Accrued interest payable on deposits including escrow	(427		)	—				(427		)	—
	Accrued interest payable on borrowings	(2,736		)	—				(2,736		)	—
	Interest rate caps and swaps	(756		)	—				(756		)	—
	The following is a summary of the carrying amounts and estimated fair values of financial assets and liabilities (none of which were held for trading purposes) as of September 30, 2013:
		September 30, 2013
		Carrying			Level 1 inputs				Level 2 inputs			Level 3 inputs
		amount
	Financial assets:
	Cash and due from banks	$	113,090		$	113,090			$	—		$	—
	Securities available for sale	954,393			—				950,780			3,613
	Securities held to maturity	253,999			—				250,896			—
	Loans, net	2,384,021			—				—			2,422,824
	Loans held for sale	1,011			—				1,011			—
	Accrued interest receivable on securities	4,892			—				4,892			—
	Accrued interest receivable on loans	6,805			—				—			6,805
	FHLB stock	24,312			—				—			—
	Interest rate caps and swaps	997			—				997			—
	Financial liabilities:
	Non-maturity deposits	(2,694,166		)	(2,694,166		)		—			—
	Certificates of deposit	(268,128		)	—				(268,088		)	—
	FHLB and other borrowings	(462,953		)	—				(488,369		)	—
	Senior Notes	(98,033		)	—				(98,142		)	—
	Mortgage escrow funds	(12,646		)	—				(12,644		)	—
	Accrued interest payable on deposits including escrow	(1,480		)	—				(1,480		)	—
	Accrued interest payable on borrowings	(1,525		)	—				(1,525		)	—
	Interest rate caps and swaps	(997		)	—				(997		)	—

Comprehensive_Income_Tables

Comprehensive Income (Tables)	6 Months Ended
	Mar. 31, 2014
Comprehensive income [Abstract]	'
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	'
	Activity in accumulated other comprehensive (loss) income (“AOCI”), net of tax, for the six month periods ended March 31, 2014 and 2013, was as follows:
		Unrealized gains(losses) on securities				Unrealized gains (losses) for pension and other post-retirement obligations			Total
	Balance at September 30, 2012	$	15,066			$	(8,167	)	$	6,899
	Other comprehensive income before reclassifications	(4,446		)		—			(4,446		)
	Amounts reclassified from AOCI	(2,146		)		612			(1,534		)
	Period change	(6,592		)		612			(5,980		)
	Balance at March 31, 2013	$	8,474			$	(7,555	)	$	919
	Balance at September 30, 2013	$	(11,472	)		$	(3,858	)	$	(15,330	)
	Other comprehensive income before reclassifications	10				—			10
	Amounts reclassified from AOCI	336				699			1,035
	Period change	346				699			1,045
	Balance at March 31, 2014	$	(11,126	)		$	(3,159	)	$	(14,285	)
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	eclassification adjustments from AOCI included in net income and the impacted line items on the income statement for the six months ended March 31, 2014:
	Components of AOCI		Amount reclassified from AOCI and impact on net income  (1)				Affected income statement line item
	Unrealized (losses) on available for sale securities:
			$	(585	)		Non-interest income - net loss on sale of securities
			249				Tax benefit
			$	(336	)		Net change after-tax
	Amortization of defined benefit pension items:
	Loss on settlement of portion of defined benefit plan		$	(1,216	)		Non-interest expense - compensation and employee benefits (2)
			517				Tax benefit
			$	(699	)		Net change after-tax
	(1) Amounts in parentheses indicate a reduction from income.
	(2) These accumulated other comprehensive income (loss) components are included in the computation of net periodic pension cost (see Note 13. - Pensions and Other Post Retirement Plans for additional details).

Acquisition_Details

Acquisition (Details) (USD $)	Mar. 31, 2014	Sep. 30, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013	Oct. 31, 2013
In Thousands, unless otherwise specified			Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]
				Core deposits and other intangibles	Trade name intangible	Book Value [Member]	Book Value [Member]	Book Value [Member]	Fair Value Adjustment [Member]	Fair Value Adjustment [Member]	Fair Value Adjustment [Member]
							Core deposits and other intangibles	Trade name intangible		Core deposits and other intangibles	Trade name intangible
Major Class of Assets Acquired and Liabilities Assumed	'	'	'	'	'	'	'	'	'	'	'
Cash and cash equivalents	'	'	$277,798	'	'	$277,798	'	'	$0	'	'
Investment securities	'	'	607,911	'	'	613,154	'	'	-5,243	'	'
Loans held for sale	'	'	30,341	'	'	30,341	'	'	0	'	'
Loans	'	'	-1,698,108	'	'	-1,704,801	'	'	-6,693	'	'
Federal Reserve Bank stock	'	'	7,680	'	'	7,680	'	'	0	'	'
Bank owned life insurance	'	'	55,374	'	'	55,374	'	'	0	'	'
Premises and equipment	'	'	23,594	'	'	21,293	'	'	2,301	'	'
Accrued interest receivable	'	'	6,590	'	'	6,590	'	'	0	'	'
Intangibles	'	'	'	20,089	20,500	'	0	0	'	20,089	20,500
Other real estate owned	'	'	5,815	'	'	1,720	'	'	4,095	'	'
Other assets	'	'	-22,551	'	'	-40,877	'	'	-18,326	'	'
Deposits	'	'	-2,297,190	'	'	-2,296,713	'	'	-477	'	'
FHLB borrowings	'	'	-100,619	'	'	-100,346	'	'	-273	'	'
Other borrowings	'	'	-62,465	'	'	-62,465	'	'	0	'	'
Subordinated debentures	'	'	-26,527	'	'	-25,774	'	'	-753	'	'
Other liabilities	'	'	-55,960	'	'	-60,462	'	'	-4,502	'	'
Total identifiable net assets	'	'	233,590	'	'	213,868	'	'	19,722	'	'
Goodwill	$387,286	$163,117	$224,169	'	'	'	'	'	'	'	'

Acquisition_Detail_1

Acquisition (Detail 1) (Sterling Bancorp (Legacy) [Member], USD $)	6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Oct. 31, 2013
Sterling Bancorp (Legacy) [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Contractual principal balance at acquisition	'	'	$24,176
Principal not expected to be collection (non-accretable discount)	'	'	-10,927
Expected cash flows at acquisition	'	'	13,249
Interest component of expected cash flows (accretable discount)	'	'	0
Fair value of acquired loans	'	'	13,249
Pro Forma Information	'	'	'
Net interest income	100,571	90,586	'
Non-interest income	28,590	34,232	'
Non-interest expense	99,368	97,026	'
Net income	$20,110	$19,970	'
Earnings per share from continuing operations, basic	$0.24	$0.24	'
Earnings per share from continuing operations, diluted	$0.24	$0.24	'

Acquisition_Detail_Textural

Acquisition (Detail Textural) (USD $)

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

0 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

In Thousands, except Share data, unless otherwise specified

Mar. 31, 2014

Sep. 30, 2013

Oct. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Aug. 10, 2012

Oct. 31, 2013

Oct. 31, 2013

Mar. 31, 2014

Oct. 31, 2013

Oct. 31, 2013

Oct. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Gotham Bank of New York [Member]

Fair Value Adjustment [Member]

Book Value [Member]

Core deposits and other intangibles

Core deposits and other intangibles

Core deposits and other intangibles

Core deposits and other intangibles

Assets Write-down, Retention, and Severance Costs [Member]

Minimum [Member]

Maximum [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Fair Value Adjustment [Member]

Book Value [Member]

Sterling Bancorp (Legacy) [Member]

Equipment [Member]

Equipment [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Percentage of Voting Interests Acquired

'

'

'

'

'

'

'

100.00%

'

'

'

'

'

'

'

'

'

Acquired Finite-lived Intangible Assets, Weighted Average Useful Life

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits

'

'

$2,297,190

'

'

'

'

'

$477

$2,296,713

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles

'

'

'

'

'

'

'

'

'

'

'

20,089

20,089

0

'

'

'

Business Acquisition, Share Price

'

'

$11.72

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Number of Shares Received by Acquiree for Each share of Acquiree's Stock

'

'

1.2625

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Equity Interest Issued or Issuable, Number of Shares

'

'

39,057,968

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Consideration Transferred

457,759

'

457,759

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill

387,286

163,117

224,169

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets

'

'

2,759,628

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Federal Home Loan Bank Stock

'

'

1,735,142

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, Plant and Equipment, Useful Life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'5 years

Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed

'

'

'

388

9,456

542

542

'

'

'

'

'

'

'

'

'

'

Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized

'

'

'

'

'

'

'

'

'

'

'

'

'

'

22,422

'

'

Payments to Acquire Businesses, Gross

'

'

'

'

'

'

'

$40,510

'

'

'

'

'

'

'

'

'

Business Acquisition, Percentage of Tangible Net Worth Used for Cash Payment

'

'

'

'

'

'

'

125.00%

'

'

'

'

'

'

'

'

'

Securities_Details

Securities (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	$1,243,027	$973,709
Available-for-sale Securities, Gross Unrealized Gain	7,190	5,805
Gross Unrealized Losses	-16,907	-25,121
Fair value	1,233,310	954,393
Mortgage-backed securities-residential [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	594,425	454,173
Available-for-sale Securities, Gross Unrealized Gain	2,160	2,205
Gross Unrealized Losses	-4,219	-7,195
Fair value	592,366	449,183
Investment securities [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	648,602	519,536
Available-for-sale Securities, Gross Unrealized Gain	5,030	3,600
Gross Unrealized Losses	-12,688	-17,926
Fair value	640,944	505,210
Agency-backed | Mortgage-backed securities-residential [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	458,121	284,837
Available-for-sale Securities, Gross Unrealized Gain	1,925	1,849
Gross Unrealized Losses	-2,531	-4,157
Fair value	457,515	282,529
CMO/Other MBS [Member] | Mortgage-backed securities-residential [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	136,304	169,336
Available-for-sale Securities, Gross Unrealized Gain	235	356
Gross Unrealized Losses	-1,688	-3,038
Fair value	134,851	166,654
Mutual funds | Investment securities [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	4,874	0
Available-for-sale Securities, Gross Unrealized Gain	0	0
Gross Unrealized Losses	-51	0
Fair value	4,823	0
US Government Corporations and Agencies Securities [Member] | Investment securities [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	217,942	273,637
Available-for-sale Securities, Gross Unrealized Gain	3	0
Gross Unrealized Losses	-8,244	-12,090
Fair value	209,701	261,547
Corporate Debt Securities [Member] | Investment securities [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	225,628	118,575
Available-for-sale Securities, Gross Unrealized Gain	180	153
Gross Unrealized Losses	-3,610	-3,795
Fair value	222,198	114,933
Obligations of states and political subdivisions [Member] | Investment securities [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	134,881	127,324
Available-for-sale Securities, Gross Unrealized Gain	3,038	3,447
Gross Unrealized Losses	-783	-2,041
Fair value	137,136	128,730
Trust Preferred Securities Subject to Mandatory Redemption [Member] | Investment securities [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	65,277	0
Available-for-sale Securities, Gross Unrealized Gain	1,809	0
Gross Unrealized Losses	0	0
Fair value	$67,086	$0

Securities_Details_1

Securities (Details 1) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	$527,265	$253,999
Gross Unrealized Gains	3,764	1,324
Gross Unrealized Losses	-3,908	-4,427
Securities held-to-maturity at fair value	527,121	250,896
Mortgage-backed securities-residential [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	196,194	156,147
Gross Unrealized Gains	704	749
Gross Unrealized Losses	-2,221	-423
Securities held-to-maturity at fair value	194,677	156,473
Investment securities [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	331,071	97,852
Gross Unrealized Gains	3,060	575
Gross Unrealized Losses	-1,687	-4,004
Securities held-to-maturity at fair value	332,444	94,423
Agency-backed | Mortgage-backed securities-residential [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	128,212	130,371
Gross Unrealized Gains	691	716
Gross Unrealized Losses	-362	-108
Securities held-to-maturity at fair value	128,541	130,979
CMO/Other MBS [Member] | Mortgage-backed securities-residential [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	67,982	25,776
Gross Unrealized Gains	13	33
Gross Unrealized Losses	-1,859	-315
Securities held-to-maturity at fair value	66,136	25,494
Federal agencies [Member] | Investment securities [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	135,998	77,341
Gross Unrealized Gains	740	0
Gross Unrealized Losses	-1,375	-3,458
Securities held-to-maturity at fair value	135,363	73,883
Obligations of states and political subdivisions [Member] | Investment securities [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	193,573	19,011
Gross Unrealized Gains	2,300	556
Gross Unrealized Losses	-312	-546
Securities held-to-maturity at fair value	195,561	19,021
Other [Member] | Investment securities [Member]	'	'
Held-to-maturity securities	'	'
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	1,500	1,500
Gross Unrealized Gains	20	19
Gross Unrealized Losses	0	0
Securities held-to-maturity at fair value	$1,520	$1,519

Securities_Details_2

Securities (Details 2) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Available for sale	'	'
Amortized Cost, Less than one year	$27,970	'
Amortized Cost, One to five years	180,125	'
Amortized Cost, Five to ten years	367,390	'
Amortized Cost, Greater than ten years	73,117	'
Available-for-sale Securities, Amortized Cost Basis	1,243,027	973,709
Fair Value, Less than one year	27,977	'
Fair Value, One to five years	179,888	'
Fair Value, Five to ten years	358,028	'
Fair Value, Greater than ten years	75,051	'
Fair value	1,233,310	954,393
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	527,265	253,999
Held to maturity	'	'
Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount	8,790	'
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	5,110	'
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	149,874	'
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	167,297	'
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount	527,265	253,999
Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value	8,874	'
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	5,356	'
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	149,293	'
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	168,921	'
Securities held-to-maturity at fair value	527,121	250,896
Securities Investment [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	648,602	519,536
Fair value	640,944	505,210
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	331,071	97,852
Held to maturity	'	'
Securities held-to-maturity at fair value	332,444	94,423
Mortgage-backed securities-residential [Member]	'	'
Available for sale	'	'
Available-for-sale Securities, Amortized Cost Basis	594,425	454,173
Fair value	592,366	449,183
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	196,194	156,147
Held to maturity	'	'
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount	196,194	'
Securities held-to-maturity at fair value	$194,677	$156,473

Securities_Details_3

Securities (Details 3) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Gain (Loss) on Investments [Line Items]	'	'	'	'
Proceeds from Sale of Available-for-sale Securities	$55,778	$94,839	$305,489	$136,804
Available-for-sale Securities, Gross Realized Gains	65	2,202	276	3,618
Available-for-sale Securities, Gross Realized Losses	-5	-10	-861	-10
Tax expense of securities gains	-18	-552	-229	-1,010
Proceeds from Sale of Held-to-maturity Securities	0	1,234	0	1,234
Held-to-maturity Securities, Sold Security, Realized Gain (Loss)	0	37	0	37
Tax expense held to maturity security gains	$0	($9)	$0	($10)

Securities_Details_4

Securities (Details 4) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	$413,977	$659,734
Unrealized Losses, Less Than 12 Months	-4,643	-24,817
Fair Value, 12 Months or Longer	359,419	7,932
Unrealized Losses, 12 Months or Longer	-12,264	-304
Fair Value, Total	773,396	667,666
Unrealized Losses, Total	-16,907	-25,121
Agency-backed	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	179,009	137,265
Unrealized Losses, Less Than 12 Months	-691	-4,157
Fair Value, 12 Months or Longer	67,082	0
Unrealized Losses, 12 Months or Longer	-1,840	0
Fair Value, Total	246,091	137,265
Unrealized Losses, Total	-2,531	-4,157
CMO/Other MBS [Member]	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	64,069	122,324
Unrealized Losses, Less Than 12 Months	-676	-2,742
Fair Value, 12 Months or Longer	27,175	7,820
Unrealized Losses, 12 Months or Longer	-1,012	-296
Fair Value, Total	91,244	130,144
Unrealized Losses, Total	-1,688	-3,038
Mortgage-backed securities-residential [Member]	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	243,078	259,589
Unrealized Losses, Less Than 12 Months	-1,367	-6,899
Fair Value, 12 Months or Longer	94,257	7,820
Unrealized Losses, 12 Months or Longer	-2,852	-296
Fair Value, Total	337,335	267,409
Unrealized Losses, Total	-4,219	-7,195
Mutual funds	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	4,827	'
Unrealized Losses, Less Than 12 Months	-51	'
Fair Value, 12 Months or Longer	0	'
Unrealized Losses, 12 Months or Longer	0	'
Fair Value, Total	4,827	'
Unrealized Losses, Total	-51	'
Federal agencies [Member]	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	51,116	261,547
Unrealized Losses, Less Than 12 Months	-2,048	-12,090
Fair Value, 12 Months or Longer	158,091	0
Unrealized Losses, 12 Months or Longer	-6,196	0
Fair Value, Total	209,207	261,547
Unrealized Losses, Total	-8,244	-12,090
Obligations of states and political subdivisions [Member]	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	28,293	43,585
Unrealized Losses, Less Than 12 Months	-252	-2,033
Fair Value, 12 Months or Longer	16,308	112
Unrealized Losses, 12 Months or Longer	-531	-8
Fair Value, Total	44,601	43,697
Unrealized Losses, Total	-783	-2,041
Corporate Debt Securities [Member]	'	'
Securities available for sale with unrealized losses	'	'
Fair Value, Less Than 12 Months	86,663	95,013
Unrealized Losses, Less Than 12 Months	-925	-3,795
Fair Value, 12 Months or Longer	90,763	0
Unrealized Losses, 12 Months or Longer	-2,685	0
Fair Value, Total	177,426	95,013
Unrealized Losses, Total	($3,610)	($3,795)

Securities_Details_5

Securities (Details 5) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less Than 12 Months	$193,267	$125,788
Unrealized Losses, Less Than 12 Months	-3,908	-4,427
Fair Value, 12 Months or Longer	0	0
Unrealized Losses, 12 Months or Longer	0	0
Fair Value, Total	193,267	125,788
Agency-backed	'	'
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less Than 12 Months	61,535	10,963
Unrealized Losses, Less Than 12 Months	'	-86
Fair Value, 12 Months or Longer	0	0
Unrealized Losses, 12 Months or Longer	0	0
Fair Value, Total	61,535	10,963
Unrealized Losses, Total	-362	-86
CMO/Other MBS [Member]	'	'
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less Than 12 Months	61,924	31,412
Unrealized Losses, Less Than 12 Months	-1,859	-337
Fair Value, 12 Months or Longer	0	0
Unrealized Losses, 12 Months or Longer	0	0
Fair Value, Total	61,924	31,412
Unrealized Losses, Total	-1,859	-337
Federal agencies [Member]	'	'
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less Than 12 Months	40,085	73,883
Unrealized Losses, Less Than 12 Months	-1,375	-3,458
Fair Value, 12 Months or Longer	0	0
Unrealized Losses, 12 Months or Longer	0	0
Fair Value, Total	40,085	73,883
Unrealized Losses, Total	-1,375	-3,458
US States and Political Subdivisions Debt Securities [Member]	'	'
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less Than 12 Months	29,723	9,530
Unrealized Losses, Less Than 12 Months	-1,312	-546
Fair Value, 12 Months or Longer	0	0
Unrealized Losses, 12 Months or Longer	0	0
Fair Value, Total	29,723	9,530
Unrealized Losses, Total	-312	-546
Residential Mortgage Backed Securities [Member]	'	'
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]	'	'
Fair Value, Less Than 12 Months	123,459	42,375
Fair Value, 12 Months or Longer	0	0
Unrealized Losses, 12 Months or Longer	0	0
Fair Value, Total	123,459	42,375
Unrealized Losses, Total	($2,221)	($423)

Securities_Details_6

Securities (Details 6) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Total Pledged Securities	$1,172,298	$1,008,466
Federal Home Loan Bank Borrowings [Member]	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Available-for-sale Securities Pledged as Collateral	268,017	199,642
Held-to-maturity Securities Pledged as Collateral	71,393	55,497
Municipal Deposits [Member]	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Available-for-sale Securities Pledged as Collateral	505,185	580,756
Held-to-maturity Securities Pledged as Collateral	322,666	167,926
Interest Rate Swap [Member]	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'
Held-to-maturity Securities Pledged as Collateral	$5,037	$4,645

Securities_Details_Textual

Securities (Details Textual) (USD $)	2 Months Ended	6 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2013	Mar. 31, 2014	Sep. 30, 2013
		Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Number Of Securities	'	224	'
Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Number Of Securities	'	150	'
Investment securities transferred from held to maturity to available for sale	$165,230	'	'
Investment securities transfered from available for sale to held to maturity	221,904	'	'
Number of fixed maturity securities past due	'	0	'
Available-for-sale Securities, Amortized Cost Basis	'	1,243,027	973,709
Unrealized gain(loss) on investment securities transferred	$9,657	$9,528	'
Life of investment securities transferred	'	'5 years 9 months	'

Loans_Details

Loans (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012
In Thousands, unless otherwise specified
Loans [Abstract]	'	'	'	'	'	'
Loans Receivable, Gross, Commercial and Industrial	$1,072,203	'	$439,787	'	'	'
Payroll financing	126,830	'	0	'	'	'
Warehouse lending	150,280	'	0	'	'	'
Factored receivables	145,979	'	0	'	'	'
Equipment financing	332,082	'	0	'	'	'
Total commercial	1,827,374	'	439,787	'	'	'
Commercial real estate	1,315,220	'	969,490	'	'	'
Multi-family	298,782	'	307,547	'	'	'
Acquisition, development & construction	90,905	'	102,494	'	'	'
Total commercial mortgage	1,704,907	'	1,379,531	'	'	'
Total commercial loans	3,532,281	'	1,819,318	'	'	'
Residential mortgage	512,875	'	400,009	'	'	'
Home equity lines of credit	152,820	'	156,995	'	'	'
Other consumer loans	46,378	'	36,576	'	'	'
Total consumer	199,198	'	193,571	'	'	'
Total loans	4,244,354	'	2,412,898	'	'	'
Allowance for loan losses	32,015	30,612	28,877	27,544	28,114	28,282
Total loans, net	$4,212,339	'	$2,384,021	'	'	'

Loans_Details_1

Loans (Details 1) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Non-Performing loans:	'	'
Current Loans	$4,120,351	$2,379,522
Non-performing loans, 30-59 Days Past Due	42,763	3,844
Non-performing loans, 60-89 Days Past Due	20,969	2,626
Non-performing loans, 90+ Days Past Due	5,394	4,099
Non accrual loans	54,877	22,807
Loans Total	4,244,354	2,412,898
Current Loans under Troubled debt restructuring	14,502	23,754
30-59 Days past due	1,241	0
60-89 Days past due	2,232	0
90 Days past due	0	141
Non- accrual	12,116	2,199
Total	30,091	26,094
Commercial And Industrial [Member]	'	'
Non-Performing loans:	'	'
Current Loans	1,068,821	438,818
Non-performing loans, 30-59 Days Past Due	617	178
Non-performing loans, 60-89 Days Past Due	355	2
Non-performing loans, 90+ Days Past Due	7	289
Non accrual loans	2,403	500
Loans Total	1,072,203	439,787
Commercial Portfolio Segment [Member]	'	'
Non-Performing loans:	'	'
Loans Total	1,072,203	'
Payroll financing [Member]	'	'
Non-Performing loans:	'	'
Current Loans	84,950	'
Non-performing loans, 30-59 Days Past Due	31,324	'
Non-performing loans, 60-89 Days Past Due	7,351	'
Non-performing loans, 90+ Days Past Due	3,205	'
Non accrual loans	0	'
Loans Total	126,830	'
Warehouse financing [Member]	'	'
Non-Performing loans:	'	'
Current Loans	150,280	'
Non-performing loans, 30-59 Days Past Due	0	'
Non-performing loans, 60-89 Days Past Due	0	'
Non-performing loans, 90+ Days Past Due	0	'
Non accrual loans	0	'
Loans Total	150,280	'
Factored Receivables [Member]	'	'
Non-Performing loans:	'	'
Current Loans	135,834	'
Non-performing loans, 30-59 Days Past Due	4,620	'
Non-performing loans, 60-89 Days Past Due	2,628	'
Non-performing loans, 90+ Days Past Due	1,905	'
Non accrual loans	992	'
Loans Total	145,979	'
Equipment Financing Receivables [Member]	'	'
Non-Performing loans:	'	'
Current Loans	330,559	'
Non-performing loans, 30-59 Days Past Due	1,077	'
Non-performing loans, 60-89 Days Past Due	170	'
Non-performing loans, 90+ Days Past Due	0	'
Non accrual loans	276	'
Loans Total	332,082	'
Commerical real estate [Member]	'	'
Non-Performing loans:	'	'
Current Loans	1,289,316	1,263,933
Non-performing loans, 30-59 Days Past Due	1,389	1,978
Non-performing loans, 60-89 Days Past Due	7,737	2,357
Non-performing loans, 90+ Days Past Due	0	1,574
Non accrual loans	16,778	7,195
Loans Total	1,315,220	1,277,037
Multi-family financing [Member]	'	'
Non-Performing loans:	'	'
Current Loans	298,782	'
Non-performing loans, 30-59 Days Past Due	0	'
Non-performing loans, 60-89 Days Past Due	0	'
Non-performing loans, 90+ Days Past Due	0	'
Non accrual loans	0	'
Loans Total	298,782	'
Acquisition, development & construction [Member]	'	'
Non-Performing loans:	'	'
Current Loans	75,115	96,306
Non-performing loans, 30-59 Days Past Due	272	768
Non-performing loans, 60-89 Days Past Due	737	0
Non-performing loans, 90+ Days Past Due	0	0
Non accrual loans	14,781	5,420
Loans Total	90,905	102,494
Residential Portfolio Segment [Member]	'	'
Non-Performing loans:	'	'
Current Loans	494,438	390,072
Non-performing loans, 30-59 Days Past Due	2,175	354
Non-performing loans, 60-89 Days Past Due	1,063	267
Non-performing loans, 90+ Days Past Due	273	1,832
Non accrual loans	14,926	7,484
Loans Total	512,875	400,009
Consumer Loan [Member]	'	'
Non-Performing loans:	'	'
Current Loans	192,256	190,393
Non-performing loans, 30-59 Days Past Due	1,289	566
Non-performing loans, 60-89 Days Past Due	928	0
Non-performing loans, 90+ Days Past Due	4	404
Non accrual loans	4,721	2,208
Loans Total	199,198	193,571
Nonperforming Financing Receivable [Member]	'	'
Non-Performing loans:	'	'
Non accrual loans	54,877	22,807
Non Performing Assets	'	'
Loans 90 days past due and still accruing	5,394	4,099
Total non-performing loans	$60,271	$26,906

Loans_Details_2

Loans (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	$30,612	$28,114	$28,877	$28,282
Charge-offs	-3,512	-3,832	-5,346	-7,246
Recoveries	-115	-662	-684	-958
Net charge-offs	-3,397	-3,170	-4,662	-6,288
Provision for losses	-4,800	-2,600	-7,800	-5,550
Ending Allowance for Loan Losses	32,015	27,544	32,015	27,544
Annualized net charge-offs to average gross loans	0.34%	0.58%	0.25%	0.58%
Commercial And Industrial [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	6,886	5,533	5,302	4,603
Charge-offs	-1,164	-359	-1,692	-518
Recoveries	-74	-127	-575	-247
Net charge-offs	-1,090	-232	-1,117	-271
Provision for losses	-873	-930	-2,484	-39
Ending Allowance for Loan Losses	6,669	4,371	6,669	4,371
Payroll financing [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	0	'	'	'
Charge-offs	0	'	0	'
Recoveries	0	'	0	'
Net charge-offs	0	'	0	'
Provision for losses	-610	'	-610	'
Ending Allowance for Loan Losses	610	'	610	'
Warehouse financing [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	0	'	'	'
Charge-offs	0	'	0	'
Recoveries	0	'	0	'
Net charge-offs	0	'	0	'
Provision for losses	-132	'	-132	'
Ending Allowance for Loan Losses	132	'	132	'
Factored Receivables [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	0	'	'	'
Charge-offs	-289	'	-289	'
Recoveries	0	'	0	'
Net charge-offs	-289	'	-289	'
Provision for losses	-668	'	-668	'
Ending Allowance for Loan Losses	379	'	379	'
Equipment Financing Receivables [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	0	'	'	'
Charge-offs	-167	'	-167	'
Recoveries	0	'	0	'
Net charge-offs	-167	'	-167	'
Provision for losses	-1,473	'	-1,473	'
Ending Allowance for Loan Losses	1,306	'	1,306	'
Commerical real estate [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	9,992	7,616	9,967	7,230
Charge-offs	-280	-1,199	-951	-1,427
Recoveries	-19	-331	-56	-412
Net charge-offs	-261	-868	-895	-1,015
Provision for losses	-1,135	-2,401	-1,794	-2,934
Ending Allowance for Loan Losses	10,866	9,149	10,866	9,149
Acquisition, development & construction [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	5,857	7,026	5,806	8,526
Charge-offs	-1,260	-567	-1,478	-2,161
Recoveries	0	-164	0	-169
Net charge-offs	-1,260	-403	-1,478	-1,992
Provision for losses	-1,038	-521	-769	432
Ending Allowance for Loan Losses	3,559	6,102	3,559	6,102
Residential Portfolio Segment [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	4,600	4,368	4,474	4,359
Charge-offs	-148	-959	-418	-1,909
Recoveries	-1	-9	-8	-60
Net charge-offs	-147	-950	-410	-1,849
Provision for losses	-112	-1,025	-501	-1,933
Ending Allowance for Loan Losses	4,565	4,443	4,565	4,443
Consumer Loan [Member]	'	'	'	'
Summary of activity in allowance for loan losses and recorded investments in loans by portfolio segment based on impairment method	'	'	'	'
Beginning Allowance for loan losses	3,277	3,571	3,328	3,564
Charge-offs	-204	-748	-351	-1,231
Recoveries	-21	-31	-45	-70
Net charge-offs	-183	-717	-306	-1,161
Provision for losses	-835	-625	-907	-1,076
Ending Allowance for Loan Losses	$3,929	$3,479	$3,929	$3,479

Loans_Details_3

Loans (Details 3) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	$37,085	$36,821
Collectively evaluated for impairment	4,194,637	2,376,077
Total loans	4,244,354	2,412,898
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	1,593
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	32,015	27,284
Financing Receivable, Allowance for Credit Losses	32,015	28,877
Commercial And Industrial [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	1,841	2,631
Collectively evaluated for impairment	1,068,031	437,156
Total loans	1,072,203	439,787
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	249
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	6,669	5,053
Financing Receivable, Allowance for Credit Losses	6,669	5,302
Commercial Real Estate Portfolio Segment [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	'	14,091
Collectively evaluated for impairment	'	1,262,946
Total loans	1,315,220	1,277,037
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	'	803
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	'	9,164
Financing Receivable, Allowance for Credit Losses	'	9,967
Payroll financing [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	0	'
Collectively evaluated for impairment	126,830	'
Total loans	126,830	'
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	'
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	610	'
Financing Receivable, Allowance for Credit Losses	610	'
Warehouse financing [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	0	'
Collectively evaluated for impairment	150,280	'
Total loans	150,280	'
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	'
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	132	'
Financing Receivable, Allowance for Credit Losses	132	'
Factored receivable [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	992	'
Collectively evaluated for impairment	144,987	'
Total loans	145,979	'
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	'
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	379	'
Financing Receivable, Allowance for Credit Losses	379	'
Equipment Financing Receivables [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	0	'
Collectively evaluated for impairment	332,082	'
Total loans	332,082	'
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	'
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,306	'
Financing Receivable, Allowance for Credit Losses	1,306	'
Commercial Real Estate [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	12,732	'
Collectively evaluated for impairment	1,594,397	'
Total loans	1,614,002	'
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	'
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	10,866	'
Financing Receivable, Allowance for Credit Losses	10,866	'
Multi-family financing [Member]	'	'
Loans evaluated for impairment by segment	'	'
Total loans	298,782	'
Acquisition, development & construction	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	21,005	19,582
Collectively evaluated for impairment	69,900	82,912
Total loans	90,905	102,494
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	540
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	3,559	5,266
Financing Receivable, Allowance for Credit Losses	3,559	5,806
Residential Portfolio Segment [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	515	515
Collectively evaluated for impairment	508,932	399,494
Total loans	512,875	400,009
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	4,565	4,474
Financing Receivable, Allowance for Credit Losses	4,565	4,474
Consumer Loan [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	0	'
Collectively evaluated for impairment	199,198	'
Total loans	199,198	193,571
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	'
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	3,929	'
Financing Receivable, Allowance for Credit Losses	3,929	'
Consumer Other Financing Receivable [Member]	'	'
Loans evaluated for impairment by segment	'	'
Individually evaluated for impairment	'	2
Collectively evaluated for impairment	'	193,569
Total loans	'	193,571
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	'	1
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	'	3,327
Financing Receivable, Allowance for Credit Losses	'	3,328
Sterling Bancorp (Legacy) [Member]	'	'
Loans evaluated for impairment by segment	'	'
Recorded investment purchased credit impaired loans	12,632	'
Sterling Bancorp (Legacy) [Member] | Commercial And Industrial [Member]	'	'
Loans evaluated for impairment by segment	'	'
Recorded investment purchased credit impaired loans	2,331	'
Sterling Bancorp (Legacy) [Member] | Commercial Real Estate [Member]	'	'
Loans evaluated for impairment by segment	'	'
Recorded investment purchased credit impaired loans	6,873	'
Sterling Bancorp (Legacy) [Member] | Acquisition, development & construction	'	'
Loans evaluated for impairment by segment	'	'
Recorded investment purchased credit impaired loans	0	'
Sterling Bancorp (Legacy) [Member] | Residential Portfolio Segment [Member]	'	'
Loans evaluated for impairment by segment	'	'
Recorded investment purchased credit impaired loans	3,428	'
Sterling Bancorp (Legacy) [Member] | Consumer Loan [Member]	'	'
Loans evaluated for impairment by segment	'	'
Recorded investment purchased credit impaired loans	$0	'

Loans_Details_4

Loans (Details 4) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
With an allowance recorded:	'	'
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	$0	$6,405
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	4,410
With no related allowance recorded:	'	'
Impaired Financing Receivable With Related Allowance Allowance Amount	0	1,593
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	37,085	32,411
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	38,110	33,112
Impaired Financing Receivable, Unpaid Principal Balance	38,110	39,517
Impaired Financing Receivable, Recorded Investment	37,085	36,821
Impaired Financing Receivable Net	0	1,593
Commercial And Industrial [Member]	'	'
With an allowance recorded:	'	'
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	500
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	500
With no related allowance recorded:	'	'
Impaired Financing Receivable With Related Allowance Allowance Amount	0	249
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,841	2,131
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,841	2,175
Factored receivable [Member]	'	'
With no related allowance recorded:	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	992	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	992	0
Commercial Real Estate [Member]	'	'
With an allowance recorded:	'	'
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	3,150
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	2,271
With no related allowance recorded:	'	'
Impaired Financing Receivable With Related Allowance Allowance Amount	0	803
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	12,732	11,820
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	12,847	12,451
Acquisition, development & construction	'	'
With an allowance recorded:	'	'
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	2,753
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	1,637
With no related allowance recorded:	'	'
Impaired Financing Receivable With Related Allowance Allowance Amount	0	540
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	21,005	17,945
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	21,915	17,971
Residential Portfolio Segment [Member]	'	'
With no related allowance recorded:	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	515	515
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	515	515
Consumer Loan [Member]	'	'
With an allowance recorded:	'	'
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	2
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	2
With no related allowance recorded:	'	'
Impaired Financing Receivable With Related Allowance Allowance Amount	$0	$1

Loans_Details_5

Loans (Details 5) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	$38,073	$36,808	$35,836	$38,274
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	106	564	250	1,134
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	290	0	578
With an allowance recorded:	'	'	'	'
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	11,839	0	11,860
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	34	0	68
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	20	0	41
Impaired Financing Receivable, Average Recorded Investment	38,073	48,647	35,836	50,134
Impaired Financing Receivable, Interest Income, Accrual Method	106	598	250	1,202
Impaired Financing Receivable, Interest Income, Cash Basis Method	0	310	0	619
Commercial And Industrial [Member]	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,850	1,873	1,853	2,067
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	45	0	90
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	21	0	42
With an allowance recorded:	'	'	'	'
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	368	0	365
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	3	0	6
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	'	3	0	6
Factored receivable [Member]	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	992	0	496	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0	0	0
Commercial Real Estate [Member]	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	12,512	9,248	12,204	9,241
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	40	99	94	199
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	53	0	105
With an allowance recorded:	'	'	'	'
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	6,265	0	6,245
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	13	0	27
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	9	0	19
Multi-family financing [Member]	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	264	0	264	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0	0	0
Acquisition, development & construction	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	21,940	15,582	20,762	16,603
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	66	313	156	630
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	161	0	321
With an allowance recorded:	'	'	'	'
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	3,857	0	656
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	14	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	6	0	0
Residential Portfolio Segment [Member]	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	515	7,978	257	8,165
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	100	0	201
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	52	0	104
With an allowance recorded:	'	'	'	'
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	649	0	3,885
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0	27
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0	0	12
Consumer Loan [Member]	'	'	'	'
With no related allowance recorded:	'	'	'	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	2,127	0	2,198
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	7	0	14
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	3	0	6
With an allowance recorded:	'	'	'	'
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	700	0	709
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	4	0	8
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	$0	$2	$0	$4

Loans_Details_6

Loans (Details 6) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Troubled debt restructurings	'	'
30-59 Days past due	$1,241	$0
60-89 Days past due	2,232	0
90 Days past due	0	141
Non- accrual	12,116	2,199
Total	30,091	26,094
Loans and Leases Receivable, Impaired, Troubled Debt, Interest Income	-14,502	-23,754
Trouble Debt restructuring currrent loans	14,502	23,754
Allowance, Current Loans	-52	-438
Allowance, 30-59 days past due	0	0
Allowance, 60-89 days past due	0	0
Allowance, 90+ days past due	0	0
Allowance, Non-Accrual	14	439
Allowance, Total TDR's	66	877
Commercial And Industrial [Member]	'	'
Troubled debt restructurings	'	'
30-59 Days past due	0	0
60-89 Days past due	0	0
90 Days past due	0	141
Non- accrual	1,623	0
Total	1,930	1,984
Trouble Debt restructuring currrent loans	307	1,843
Commercial Real Estate Portfolio Segment [Member]	'	'
Troubled debt restructurings	'	'
30-59 Days past due	'	0
60-89 Days past due	'	0
90 Days past due	'	0
Non- accrual	'	0
Total	'	5,305
Trouble Debt restructuring currrent loans	'	5,305
Commercial Real Estate [Member]	'	'
Troubled debt restructurings	'	'
30-59 Days past due	0	'
60-89 Days past due	2,232	'
90 Days past due	0	'
Non- accrual	448	'
Total	5,293	'
Trouble Debt restructuring currrent loans	2,613	'
Acquisition, development & construction	'	'
Troubled debt restructurings	'	'
30-59 Days past due	272	0
60-89 Days past due	0	0
90 Days past due	0	0
Non- accrual	6,956	151
Total	13,318	14,341
Trouble Debt restructuring currrent loans	6,090	14,190
Residential Portfolio Segment [Member]	'	'
Troubled debt restructurings	'	'
30-59 Days past due	969	0
60-89 Days past due	0	0
90 Days past due	0	0
Non- accrual	2,868	1,792
Total	9,329	4,208
Trouble Debt restructuring currrent loans	5,492	2,416
Consumer Loan [Member]	'	'
Troubled debt restructurings	'	'
30-59 Days past due	0	'
60-89 Days past due	0	'
90 Days past due	0	'
Non- accrual	221	'
Total	221	'
Trouble Debt restructuring currrent loans	0	'
Consumer Other Financing Receivable [Member]	'	'
Troubled debt restructurings	'	'
30-59 Days past due	'	0
60-89 Days past due	'	0
90 Days past due	'	0
Non- accrual	'	256
Total	'	256
Trouble Debt restructuring currrent loans	'	$0

Loans_Details_7

Loans (Details 7) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
	loans	loans	loans	loans
Restructured Loans:	'	'	'	'
Number of loans	2	7	2	12
Pre-Modification	$1,060	$3,218	$1,060	$8,166
Post-Modification	1,060	3,218	1,060	8,166
Commercial And Industrial [Member]	'	'	'	'
Restructured Loans:	'	'	'	'
Number of loans	0	2	0	3
Pre-Modification	0	169	0	1,669
Post-Modification	0	169	0	1,669
Commercial Real Estate [Member]	'	'	'	'
Restructured Loans:	'	'	'	'
Number of loans	'	'	0	1
Pre-Modification	'	'	0	450
Post-Modification	'	'	0	450
Acquisition, development & construction	'	'	'	'
Restructured Loans:	'	'	'	'
Number of loans	2	5	2	7
Pre-Modification	1,060	3,049	1,060	5,772
Post-Modification	1,060	3,049	1,060	5,772
Residential Portfolio Segment [Member]	'	'	'	'
Restructured Loans:	'	'	'	'
Number of loans	'	'	0	1
Pre-Modification	'	'	0	275
Post-Modification	'	'	$0	$275

Loans_Details_8

Loans (Details 8) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Doubtful [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	$2	$592
Doubtful [Member] | Commercial And Industrial [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	2	365
Doubtful [Member] | Factored receivable [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	0
Doubtful [Member] | Equipment Financing Receivables [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	'
Doubtful [Member] | Finance Leases Portfolio Segment [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	'	0
Doubtful [Member] | Commerical real estate [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	227
Doubtful [Member] | Multi-family financing [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	0
Doubtful [Member] | Acquisition, development & construction [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	0
Doubtful [Member] | Residential Portfolio Segment [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	0
Doubtful [Member] | Consumer [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	0
Substandard [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	82,671	60,503
Substandard [Member] | Commercial And Industrial [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	7,731	3,855
Substandard [Member] | Factored receivable [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	992	0
Substandard [Member] | Equipment Financing Receivables [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	276	'
Substandard [Member] | Finance Leases Portfolio Segment [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	'	0
Substandard [Member] | Commerical real estate [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	33,627	24,561
Substandard [Member] | Multi-family financing [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	617	0
Substandard [Member] | Acquisition, development & construction [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	18,555	19,410
Substandard [Member] | Residential Portfolio Segment [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	15,732	9,786
Substandard [Member] | Consumer [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	5,141	2,891
Special Mention [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	39,964	13,530
Special Mention [Member] | Commercial And Industrial [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	25,620	3,545
Special Mention [Member] | Factored receivable [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	1,743	0
Special Mention [Member] | Equipment Financing Receivables [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	'
Special Mention [Member] | Finance Leases Portfolio Segment [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	'	0
Special Mention [Member] | Commerical real estate [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	8,813	7,279
Special Mention [Member] | Multi-family financing [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	0	0
Special Mention [Member] | Acquisition, development & construction [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	1,060	1,867
Special Mention [Member] | Residential Portfolio Segment [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	1,805	824
Special Mention [Member] | Consumer [Member]	'	'
Risk category of loans by segment of gross loans	'	'
Risk Category of loans by Segment of loans	$923	$15

Loans_Details_Textual

Loans (Details Textual) (USD $)	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Oct. 31, 2013	Sep. 30, 2013
Loans (Textual) [Abstract]	'	'	'	'	'
Net deferred loan origination Fees and Costs	'	($1,109,000)	'	'	($1,201,000)
Increased allowance for loan losses	0	0	218,000	'	'
Charge offs resulting from troubled debt restructurings	0	736,000	'	'	'
Legacy Sterling loans not considered impaired	'	'	'	1,683,454,000	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Carrying amount of Acquired legacy Sterling Loans	'	11,305,000	'	'	'
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	'	0	'	'	'
Pledged Assets Separately Reported, Loans Pledged as Collateral, at Fair Value	'	924,115,000	'	'	784,422,000
Additional restricted loan [Member]	'	'	'	'	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Additional restricted loan	'	0	'	'	4,101,000
Sterling Bancorp (Legacy) [Member]	'	'	'	'	'
Loans (Textual) [Abstract]	'	'	'	'	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans	'	'	'	1,698,108,000	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Certain Loans Acquired in Transfer, Accretable Yield	'	0	'	'	'
Sterling Bancorp (Legacy) [Member]	'	'	'	'	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Financing Receivable, Acquired with Deteriorated Credit Quality	'	12,632,000	'	'	'
Impaired [Member] | Sterling Bancorp (Legacy) [Member]	'	'	'	'	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Financing Receivable, Acquired with Deteriorated Credit Quality	'	'	'	14,654,000	'
Carrying amount of loans not impaired [Domain] | Gotham Bank of New York / legacy Sterling Bancorp [Member]	'	'	'	'	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Acquired	'	1,378,608,000	'	'	'
Commercial And Industrial [Member] | Sterling Bancorp (Legacy) [Member]	'	'	'	'	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Financing Receivable, Acquired with Deteriorated Credit Quality	'	2,331,000	'	'	'
Commercial And Industrial [Member] | Purchased credit impaired loans [Member] | Sterling Bancorp (Legacy) [Member]	'	'	'	'	'
Financing Receivable, Allowance for Credit Losses [Line Items]	'	'	'	'	'
Impaired Financing Receivable, Related Allowance	'	$0	'	'	'

Deposits_Details

Deposits (Details) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Summary of major classification of deposits	'	'
Noninterest-bearing Domestic Deposit, Demand	$1,687,775	$943,934
Interest-bearing Domestic Deposit, Demand	744,701	434,398
Savings	607,601	580,125
Money market	1,637,838	735,709
Certificates Of Deposit	533,809	268,128
Total deposits	$5,211,724	$2,962,294

Deposits_Details_1

Deposits (Details 1) (USD $)	Mar. 31, 2014		Sep. 30, 2013
In Thousands, unless otherwise specified
Schedule of Classification of Deposits [Line Items]	'		'
Noninterest-bearing Domestic Deposit, Brokered	$95,631		$36,682
Money Market Deposits [Member]	'		'
Schedule of Classification of Deposits [Line Items]	'		'
Noninterest-bearing Domestic Deposit, Brokered	59,131		34,571
Reciprocal CDAR's [Member]	'		'
Schedule of Classification of Deposits [Line Items]	'		'
Noninterest-bearing Domestic Deposit, Brokered	33,243	[1]	1,343	[1]
CDAR's One Way [Member]	'		'
Schedule of Classification of Deposits [Line Items]	'		'
Noninterest-bearing Domestic Deposit, Brokered	$3,257		$768
[1]	Certificate of deposit account registry service.

Deposits_Details_Textual

Deposits (Details Textual) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Deposits (Textual) [Abstract]	'	'
Municipal deposits	$926,618	$757,066

Borrowings_Details

Borrowings (Details) (USD $)	Mar. 31, 2014	Sep. 30, 2013	Jul. 02, 2013
In Thousands, unless otherwise specified
By period to maturity:	'	'	'
Less than one year, Amount	$109,328	$158,897	'
Less than one year, Rate	1.01%	0.95%	'
One to two years, Amount	145,224	78,717	'
One to two years, Rate	0.56%	1.97%	'
Two to three years, Amount	132,614	191	'
Two to three years, Rate	3.43%	5.32%	'
Three to four years, Amount	120,000	202,414	'
Three to four years, Rate	4.10%	4.21%	'
Four to five years, Amount	98,215	118,033	'
Four to five years, Rate	5.98%	5.57%	'
Greater than five years, Amount	2,626	2,734	'
Greater than five years, Rate	4.92%	4.92%	'
Total borrowings, Amount	608,007	560,986	'
Total borrowings, Rate	2.86%	3.26%	'
FHLB Advances [Member]	'	'	'
By period to maturity:	'	'	'
Total borrowings, Amount	489,801	442,602	'
Total borrowings, Rate	2.34%	2.77%	'
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]	'	'	'
By period to maturity:	'	'	'
Total borrowings, Amount	19,991	20,351	'
Total borrowings, Rate	0.36%	0.88%	'
Senior Notes [Member]	'	'	'
By period to maturity:	'	'	'
Total borrowings, Amount	$98,215	$98,033	$100,000
Total borrowings, Rate	5.98%	5.98%	'

Borrowings_Details_Textual

Borrowings (Details Textual) (USD $)	6 Months Ended	12 Months Ended			12 Months Ended			6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2013	Mar. 31, 2014	Jul. 02, 2013	Mar. 31, 2014	Mar. 31, 2014
			Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]	Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]	Senior Notes [Member]	Senior Notes [Member]	Senior Notes [Member]	Sterling Bancorp (Legacy) [Member]	Sterling Bancorp (Legacy) [Member]
									Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Borrowings (Textual) [Abstract]	'	'	'	'	'	'	'	'	'
Debt Issuance Cost	'	'	'	'	$303	'	'	'	'
Repurchase agreements	10,000	'	'	'	'	'	'	'	'
Debt, Weighted Average Interest Rate	4.23%	4.23%	'	'	'	'	'	'	0.36%
Debt Instrument, Unamortized Discount	'	'	'	'	1,967	1,785	'	'	'
Interest expense cost over the life of Senior note	5.98%	'	'	'	'	'	'	'	'
Private placement discount rate	'	1.75%	'	'	'	'	'	'	'
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	'	'	'	'	'	'	5.50%	'	'
Bank pledged mortgages	924,115	784,422	'	'	'	'	'	'	'
Long-term Debt	608,007	560,986	19,991	20,351	98,033	98,215	100,000	'	'
Market Value Of Mortgage Not Required To Be Pledged	720,074	'	'	'	'	'	'	'	'
Federal home loan bank borrowings	$200,000	$200,000	'	'	'	'	'	'	'
Long term debt weighted average remaining term	'3 years 0 months 22 days	'3 years 6 months 22 days	'	'	'	'	'	'	'
Amount of repurchase agreements	2	'	'	'	'	'	'	'	'
Long-term Debt, Weighted Average Interest Rate	2.86%	3.26%	0.36%	0.88%	5.98%	5.98%	'	'	'
Repurchase agreement remaining terms	'	'	'	'	'	'	'	'0 years 0 months 20 days	'

Subordinated_Debentures_Detail

Subordinated Debentures (Details) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Subordinated Debentures [Abstract]	'	'
Subordinated debentures	$25,774	$0
Amortization of Debt Discount (Premium)	735	0
Subordinated debentures	$26,509	$0

Subordinated_debentures_textur

Subordinated debentures textural (Details1) (USD $)	Mar. 31, 2014	Sep. 30, 2013	Feb. 28, 2002	Feb. 28, 2002	Apr. 30, 2014	Mar. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified				Sterling Bancorp Trust I [Member]	Trust Preferred Securities Subject to Mandatory Redemption [Member]	Trust Preferred Securities Subject to Mandatory Redemption [Member]	Trust Preferred Securities Subject to Mandatory Redemption [Member]
					Sterling Bancorp [Member]	Sterling Bancorp [Member]
Subordinated Borrowing [Line Items]	'	'	'	'	'	'	'
Proceeds from Issuance of Trust Preferred Securities	'	'	'	$25,000	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	'	8.38%	'	'	'	'
Securities available for sale	1,233,310	954,393	'	'	'	1,013	'
Trust preferred capital securities not owned	23,987	'	'	'	'	'	'
Junior Subordinated Notes	25,774	0	'	'	'	'	'
Subsequent Event, Description	'	'	'	'	'1	'	'
Debt Instrument, Unamortized Premium	'	'	'	'	'	'	$735

Guarantors_Obligations_Under_G1

Guarantor's Obligations Under Guarantees (Details) (USD $)	Mar. 31, 2014
Guarantor's Obligations Under Guarantees (Textual) [Abstract]	'
Outstanding letters of credit	$75,931,000
Outstanding letters of credit cash secured	21,000,000
Outstanding letters of credit secured by collateral	$14,000,000

Earnings_Per_Common_Share_Deta

Earnings Per Common Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Computation of basic and diluted earnings per share	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	653,146	1,332,619	849,188	1,344,024
Basic earnings per common share	'	'	'	'
Weighted average common shares outstanding (basic)	83,497,765	43,743,640	76,924,082	43,704,163
Net income	$10,332	$6,529	($3,671)	$13,549
Basic earnings per common share	$0.12	$0.15	($0.05)	$0.31
Diluted earnings per common share	'	'	'	'
Weighted average common shares outstanding (basic)	83,497,765	43,743,640	76,924,082	43,704,163
Effect of common stock equivalents	296,342	104,846	0	86,752
Weighted average common shares diluted	83,794,107	43,848,486	76,924,082	43,790,915
Net income	$10,332	$6,529	($3,671)	$13,549
Diluted earnings per common share	$0.12	$0.15	($0.05)	$0.31

Other_Noninterest_expense_Deta

Other Non-interest expense (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Other Non-Interest Expense [Abstract]	'	'	'	'
General Insurance Expense	$637	$213	$1,217	$468
Marketing and Advertising Expense	422	535	731	779
Professional Fees	1,500	912	3,319	2,128
Information Technology and Data Processing	663	823	1,258	1,471
Other non interest expense -misc	4,852	1,820	9,426	4,130
Other Noninterest Expense	$8,074	$4,303	$15,951	$8,976

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (Restricted Stock Units (RSUs) [Member])	6 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Restricted Stock Units (RSUs) [Member]	'		'
Fair value of options granted determined using weighted-average assumptions as grant date	'		'
Risk-free interest rate	1.74%		0.96%
Expected stock price volatility	26.50%		40.80%
Dividend yield	2.05%	[1]	2.61%	[1]
Expected term in years	'5 years 9 months		'5 years 9 months 0 days
[1]	Represents the approximate annualized cash dividend rate paid with respect to a share of common stock at or near the grant date

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 1) (USD $)	6 Months Ended
	Mar. 31, 2014
Summary of Company's stock option activity	'
Granted, Number of Shares	595,435
Exercised, Number of Shares	0
Forfeited, Number of Shares	-331,694
Outstanding at end of period, Number of Shares	4,275,940
Summary of Company's stock option activity, weighted average exercise price	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period	5,000
Stock Compensation Plan [Member]	'
Summary of Company's stock option activity	'
Exercisable at end of period, Number of Shares	1,058,882
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	12.08
Summary of Company's stock option activity, weighted average exercise price	'
Exercisable at end of period, Weighted Average Exercise Price (USD per share)	11.24
2014 Stock Incentive Plan [Member] [Member]	'
Summary of Company's stock option activity	'
Granted, Number of Shares	3,400,000
Recognition and Retention Plan [Member] | Restricted Stock Units (RSUs) [Member]	'
Summary of restricted stock award activity	'
Nonvested shares at beginning of period, Number of Shares	209,697
Granted, Number of Shares	-101,078
Vested, Number of Shares	-46,590
Forfeited, Number of Shares	-15,996
Nonvested shares at end of period, Number of Shares	600,153
Summary of restricted stock award activity, weighted average grant date fair value	'
Nonvested shares at beginning of period, Weighted Average Grant-Date Fair Value	8.73
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	11.36
Vested, Weighted Average Grant-Date Fair Value	8.75
Forfeited, Weighted Average Grant-Date Fair Value	8.86
Nonvested shares at end of period, Weighted Average Grant-Date Fair Value	10.89
Employee Stock Option [Member]	'
Summary of Company's stock option activity	'
Outstanding at beginning of period, Number of Shares	2,114,509
Granted, Number of Shares	249,862
Exercised, Number of Shares	-432,056
Forfeited, Number of Shares	-274,109
Outstanding at end of period, Number of Shares	1,762,358
Summary of Company's stock option activity, weighted average exercise price	'
Outstanding at beginning of period, Weighted Average Exercise Price (USD per share)	10.71
Granted, Weighted Average Exercise Price (USD per share)	11.36
Exercised, Weighted Average Exercise Price (USD per share)	11.79
Outstanding at end of period, Weighted Average Exercise Price (USD per share)	10.53
Stock Compensation Grants associated with legacy Sterling Merger [Member]	'
Summary of Company's stock option activity	'
Granted, Number of Shares	921,503
Stock Compensation Grants associated with legacy Sterling Merger [Member] | Recognition and Retention Plan [Member] | Restricted Stock Units (RSUs) [Member]	'
Summary of restricted stock award activity	'
Granted, Number of Shares	-351,964
Summary of restricted stock award activity, weighted average grant date fair value	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	11.72
Stock Compensation Grants associated with legacy Sterling Merger [Member] | Employee Stock Option [Member]	'
Summary of Company's stock option activity	'
Granted, Number of Shares	104,152
Summary of Company's stock option activity, weighted average exercise price	'
Granted, Weighted Average Exercise Price (USD per share)	14.25

StockBased_Compensation_Detail2

Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2013
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost	'	'	$0	'	'
Total compensation cost that has been charged against income for share based compensation plan	927,000	679,000	1,918,000	1,179,000	'
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	'	'	0	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	595,435	'	'
Shares remaining that are authorized and available for future grant under the 2004 RRP	77	'	77	'	2,066,184
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	'	'	331,694	'	'
Weighted average fair value of options granted	'	'	$2.49	$2.74	'
Total unrecognized compensation cost related to non-vested shares granted under the 2004 RRP	1,422,000	'	1,422,000	'	'
Weighted-average period total unrecognized compensation cost related to non-vested shares granted under the 2004 RRP	'	'	'1 year 10 months 0 days	'	'
2014 Stock Incentive Plan [Member] [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	3,400,000	'	'
Number of shares received for each share granted	'	'	3.5	'	'
Employee Stock Option [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	249,862	'	'
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	'	'	$11.36	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	'	'	274,109	'	'
2012 Stock Plan [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	1,557,622	'	'
Number of shares received for each share granted	'	'	3.6	'	'
Recognition and Retention Plan [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Total unrecognized compensation cost related to non-vested shares granted under the 2004 RRP	5,192,000	'	5,192,000	'	'
Weighted-average period total unrecognized compensation cost related to non-vested shares granted under the 2004 RRP	'	'	'2 years 3 months 8 days	'	'
Employee Stock Option [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Total compensation cost that has been charged against income for share based compensation plan	$927,000	$679,000	$1,918,000	$1,179,000	'
Restricted Stock Units (RSUs) [Member] | Recognition and Retention Plan [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	'	'	101,078	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	'	'	$11.36	'	'
Employee Stock Option [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Term of Contract	'	'	'10 years 0 months 0 days	'	'
Employee Stock Option [Member] | Minimum [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Vesting period for Option awards	'	'	'2 years 0 months 0 days	'	'
Employee Stock Option [Member] | Maximum [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Vesting period for Option awards	'	'	'5 years 0 months 0 days	'	'
Share Option Plan 2004 [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	230,281	'	'
Sterling Bancorp (Legacy) [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	'	'	9,468	'	'
Sterling Bancorp (Legacy) [Member] | Sterling Bancorp 2013 Employment Inducement Award Plan [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	95,991	'	'
Sterling Bancorp (Legacy) [Member] | Maximum [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Vesting period for Option awards	'	'	'3 years	'	'
Sterling Bancorp (Legacy) [Member] | Fully Vested legacy Sterling options [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	110,470	'	'
Sterling Bancorp (Legacy) [Member] | Restricted Stock Units (RSUs) [Member] | 2012 Stock Plan [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	'	'	255,973	'	'
Stock Compensation Grants associated with legacy Sterling Merger [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	921,503	'	'
Stock Compensation Grants associated with legacy Sterling Merger [Member] | Employee Stock Option [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Grant of share options to employees as per Employee Share Option Plan (stock option plan)	'	'	104,152	'	'
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	'	'	$14.25	'	'
Stock Compensation Grants associated with legacy Sterling Merger [Member] | Restricted Stock Units (RSUs) [Member] | Recognition and Retention Plan [Member]	'	'	'	'	'
Stock Based Compensation (Textual) [Abstract]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	'	'	351,964	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	'	'	$11.72	'	'

Pension_and_Other_Post_Retirem2

Pension and Other Post Retirement Plans (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Pension Plan [Member]	'	'	'	'
Net post-retirement cost, recorded within salaries and employee benefits expense	'	'	'	'
Service cost	$0	$0	$0	$0
Interest cost	1,377	363	1,779	726
Expected return on plan assets	-1,701	-615	-2,372	-1,231
Amortization of net transition obligation	0	0	0	0
Amortization of prior service cost	0	0	0	0
Amortization of (gain) or loss	48	515	145	1,031
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	-1,352	0	-4,095	0
Total cost	1,076	263	3,647	526
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Net post-retirement cost, recorded within salaries and employee benefits expense	'	'	'	'
Service cost	0	11	0	23
Interest cost	11	31	23	63
Expected return on plan assets	32	0	66	0
Amortization of net transition obligation	6	6	12	12
Amortization of prior service cost	12	12	24	23
Amortization of (gain) or loss	0	-6	0	-13
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	0	0	0	0
Total cost	$61	$54	$125	$108

Pension_and_Other_Post_Retirem3

Pension and Other Post Retirement Plans (Details) (Textual) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

6 Months Ended

6 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Sep. 30, 2013

Oct. 31, 2013

Oct. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Feb. 04, 2014

Feb. 04, 2014

Mar. 31, 2014

Sep. 30, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 28, 2014

Supplemental Employee Retirement Plan, Defined Benefit [Member]

Supplemental Employee Retirement Plan, Defined Benefit [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Employee Stock Ownership Plan [Member]

Employee Stock Ownership Plan [Member]

Employee Stock Ownership Plan (ESOP) loan repayment [Member]

Legacy Provident [Domain]

Legacy Provident [Domain]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Sterling Bancorp (Legacy) [Member]

Supplemental Employee Retirement Plan, Defined Benefit [Member]

legacy Sterling/ National Bank employees' Retirement Plan [Member]

Unfunded post retirement obligation, Insurance benefits [Member]

Unfunded post retirement obligation, Insurance benefits [Member]

Unfunded post retirement obligation, Insurance benefits [Member]

United States Pension Plan of US Entity, Defined Benefit [Member]

United States Pension Plan of US Entity, Defined Benefit [Member]

United States Pension Plan of US Entity, Defined Benefit [Member]

United States Pension Plan of US Entity, Defined Benefit [Member]

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business combination pension liability assumed

'

'

'

'

'

'

$41,412,000

'

'

'

'

'

'

'

'

'

'

'

'

Employee Stock Ownership Plan (ESOP), Number of Allocated Shares

'

'

'

'

'

'

'

'

'

'

'

'

10,927

'

'

'

'

'

'

Defined benefit plan contributions by employer supplemental (SERP)

95,000

9,000

159,000

18,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock ownership plan percent automatically vested upon termination

'

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Periodic pension expense for the supplemental plan

61,000

54,000

125,000

101,000

'

'

'

'

134,000

204,000

'

'

'

'

'

'

1,208,000

'

'

Pension plan termination charge

'

'

1,352,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Pension Benefit

'

'

-144,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation

'

'

'

'

1,141,000

1,203,000

'

'

'

'

'

'

'

'

19,466,000

31,705,000

'

27,946,000

'

Settlement of a portion of pension plan liability through acquisition of annuity contracts

'

'

'

'

'

'

'

'

'

'

'

'

'

'

13,698,000

'

'

'

28,835,000

Defined Benefit Plan, Funded Status of Plan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,096,000

3,712,000

16,700,000

'

'

Accelerated amortization of accumulated other comprehensive income (loss)

'

'

2,743,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase

'

'

'

'

'

'

'

4.40%

'

'

'

'

'

'

'

'

'

'

'

Defined Benefit Plan, Fair Value of Plan Assets

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

44,700,000

'

'

Post-retirement benefit obligation

'

'

'

'

'

'

'

'

'

'

8,932,000

'

'

'

'

'

'

'

'

Employee Stock Ownership Plan (ESOP), Shares in ESOP

'

'

'

'

'

'

'

'

'

'

'

'

499,330

488,403

'

'

'

'

'

Employee Stock Ownership Plan (ESOP), Debt Structure, Direct Loan, Amount

'

'

'

'

'

'

'

'

'

'

'

'

5,983,000

'

'

'

'

'

'

Employee Stock Ownership Plan (ESOP), Compensation Expense

'

'

'

'

'

'

'

'

'

'

'

286,000

'

'

'

'

'

'

'

Employee Stock Option Plan (ESOP) plan termination cost

'

'

$134,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivatives_Details

Derivatives (Details) (USD $)	6 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Interest Rate Caps [Member]	'	'
Summary of derivatives	'	'
Notional amount	$50,000	$50,000
Weighted average maturity (in years)	'0 years 8 months 5 days	'1 year 2 months 5 days
Weighted average fixed rate	3.75%	3.75%
Fair value	0	0
3rd party interest rate swap [Member]	'	'
Summary of derivatives	'	'
Notional amount	53,141	54,180
Weighted average maturity (in years)	'5 years 3 months 5 days	'5 years 9 months 5 days
Weighted average fixed rate	4.22%	4.22%
Basis Spread on Variable Rate	2.45%	2.45%
Fair value	'	997
3rd party interest rate swap [Member] | One Month Libor [Member]	'	'
Summary of derivatives	'	'
Weighted average variable rate	'1 m Libor + 2.45	'1 m Libor + 2.45
Customer interest rate swap [Member]	'	'
Summary of derivatives	'	'
Notional amount	53,141	54,180
Weighted average maturity (in years)	'5 years 3 months 5 days	'5 years 9 months 5 days
Weighted average fixed rate	4.22%	4.22%
Basis Spread on Variable Rate	2.45%	2.45%
Fair value	$756	$997
Customer interest rate swap [Member] | One Month Libor [Member]	'	'
Summary of derivatives	'	'
Weighted average variable rate	'1 m Libor + 2.45	'1 m Libor + 2.45

Derivatives_Details_Textual

Derivatives (Details Textual) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2009
			Derivatives
Credit Derivatives [Line Items]	'	'	'
Securities pledged as collateral for Dervatives Amortized cost	$5,037	'	'
Securities pledged as collteral for derivatives at fair vaue	4,700	'	'
Interest Rate Caps [Member]	'	'	'
Credit Derivatives [Line Items]	'	'	'
Number of interest rate derivatives held	'	'	2
Strike price	'	'	3.50%
Changes in fair value	$0	$1	'
Interest Rate Cap 2 [Member]	'	'	'
Credit Derivatives [Line Items]	'	'	'
Strike price	'	'	4.00%

Fair_Value_Measurements_Detail

Fair Value Measurements (Details 1) (USD $)	Mar. 31, 2014	Sep. 30, 2013
Investment securities	'	'
Fair value	$1,233,310,000	$954,393,000
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	'	114,933,000
Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	592,366,000	449,183,000
Investment securities	'	'
Investments, Fair Value Disclosure	640,944,000	505,210,000
Fair value	1,233,310,000	954,393,000
Interest rate caps and swaps	756,000	997,000
Total assets measured at estimated fair value on a recurring basis	1,234,066,000	955,390,000
Interest rate swaps	-756,000	-997,000
Total liabilities measured at estimated fair value on a recurring basis	756,000	997,000
Fair Value Measurements [Member] | Fannie Mae [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	457,515,000	282,529,000
Fair Value Measurements [Member] | CMO/Other MBS [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	131,621,000	163,041,000
Fair Value Measurements [Member] | Privately issued collateralized mortgage obligations [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	3,230,000	3,613,000
Fair Value Measurements [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Fair Value Measurements [Member] | Federal Agencies [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	209,701,000	261,547,000
Fair Value Measurements [Member] | Corporate Bond Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	222,198,000	'
Fair Value Measurements [Member] | Obligations of states and political subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	137,136,000	128,730,000
Fair Value Measurements [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	67,086,000	'
Fair Value Measurements [Member] | Mutual funds | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	4,823,000	'
Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	'	0
Fair value	0	0
Interest rate caps and swaps	0	0
Interest rate swaps	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Fair value	0	0
Interest rate caps and swaps	0	0
Total assets measured at estimated fair value on a recurring basis	0	0
Interest rate swaps	0	0
Total liabilities measured at estimated fair value on a recurring basis	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Fannie Mae [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | CMO/Other MBS [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Privately issued collateralized mortgage obligations [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Federal Agencies [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	'	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Corporate Bond Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Obligations of states and political subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	0
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Quoted Prices in Active markets for Identical Assets Level 1 [Member] | Mutual funds | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Significant Other Observable Inputs Level 2 [Member]	'	'
Investment securities	'	'
Fair value	1,230,080,000	950,780,000
Interest rate caps and swaps	756,000	997,000
Interest rate swaps	-756,000	-997,000
Significant Other Observable Inputs Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	589,136,000	445,570,000
Investment securities	'	'
Investments, Fair Value Disclosure	640,944,000	505,210,000
Fair value	1,230,080,000	950,780,000
Interest rate caps and swaps	756,000	997,000
Total assets measured at estimated fair value on a recurring basis	1,230,836,000	951,777,000
Interest rate swaps	-756,000	-997,000
Total liabilities measured at estimated fair value on a recurring basis	756,000	997,000
Significant Other Observable Inputs Level 2 [Member] | Fannie Mae [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	457,515,000	282,529,000
Significant Other Observable Inputs Level 2 [Member] | CMO/Other MBS [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	131,621,000	163,041,000
Significant Other Observable Inputs Level 2 [Member] | Privately issued collateralized mortgage obligations [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Significant Other Observable Inputs Level 2 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Significant Other Observable Inputs Level 2 [Member] | Federal Agencies [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	209,701,000	261,547,000
Significant Other Observable Inputs Level 2 [Member] | Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	'	114,933,000
Significant Other Observable Inputs Level 2 [Member] | Corporate Bond Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	222,198,000	'
Significant Other Observable Inputs Level 2 [Member] | Obligations of states and political subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	137,136,000	128,730,000
Significant Other Observable Inputs Level 2 [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	67,086,000	'
Significant Other Observable Inputs Level 2 [Member] | Mutual funds | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	4,823,000	'
Significant Unobservable Inputs Level 3 [Member]	'	'
Investment securities	'	'
Fair value	3,230,000	3,613,000
Interest rate caps and swaps	0	0
Interest rate swaps	0	0
Significant Unobservable Inputs Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	3,230,000	3,613,000
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Fair value	3,230,000	3,613,000
Interest rate caps and swaps	0	0
Total assets measured at estimated fair value on a recurring basis	3,230,000	3,613,000
Interest rate swaps	0	0
Total liabilities measured at estimated fair value on a recurring basis	0	0
Significant Unobservable Inputs Level 3 [Member] | Fannie Mae [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Significant Unobservable Inputs Level 3 [Member] | CMO/Other MBS [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	0	0
Significant Unobservable Inputs Level 3 [Member] | Privately issued collateralized mortgage obligations [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Mortgage-backed securities-residential	'	'
Mortgage-backed securities-residential	3,230,000	3,613,000
Significant Unobservable Inputs Level 3 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Significant Unobservable Inputs Level 3 [Member] | Federal Agencies [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	0
Significant Unobservable Inputs Level 3 [Member] | Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	'	0
Significant Unobservable Inputs Level 3 [Member] | Corporate Bond Securities [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Significant Unobservable Inputs Level 3 [Member] | Obligations of states and political subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	0
Significant Unobservable Inputs Level 3 [Member] | Trust Preferred Securities Subject to Mandatory Redemption [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Significant Unobservable Inputs Level 3 [Member] | Mutual funds | Fair Value, Measurements, Recurring [Member]	'	'
Investment securities	'	'
Investments, Fair Value Disclosure	0	'
Mortgage-backed securities-residential [Member]	'	'
Investment securities	'	'
Fair value	$592,366,000	$449,183,000

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	Mar. 31, 2014	Sep. 30, 2013
In Thousands, unless otherwise specified
Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	$0	$0
Significant Other Observable Inputs Level 2 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Significant Unobservable Inputs Level 3 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	4,254,200	2,422,824
Impaired [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	3,359	6,013
Impaired [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Impaired [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs Level 2 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Impaired [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs Level 3 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	3,359	6,013
Impaired [Member] | Commercial And Industrial [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	500
Impaired [Member] | Commercial And Industrial [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	0
Impaired [Member] | Commercial And Industrial [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs Level 2 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	0
Impaired [Member] | Commercial And Industrial [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs Level 3 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	500
Impaired [Member] | Commercial Real Estate [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	897	3,672
Impaired [Member] | Commercial Real Estate [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Impaired [Member] | Commercial Real Estate [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs Level 2 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Impaired [Member] | Commercial Real Estate [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs Level 3 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	897	3,672
Impaired [Member] | Acquisition, development and construction [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	2,462	1,839
Impaired [Member] | Acquisition, development and construction [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Impaired [Member] | Acquisition, development and construction [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs Level 2 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	0	0
Impaired [Member] | Acquisition, development and construction [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs Level 3 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	2,462	1,839
Impaired [Member] | Consumer loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	2
Impaired [Member] | Consumer loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active markets for Identical Assets Level 1 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	0
Impaired [Member] | Consumer loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs Level 2 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	0
Impaired [Member] | Consumer loans [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs Level 3 [Member]	'	'
Impaired loans measured at estimated fair value on nonrecurring basis	'	'
Loans, net	'	$2

Recovered_Sheet1

Fair value measurements (Details 3) (USD $)

Mar. 31, 2014

Sep. 30, 2013

Mar. 31, 2014

Sep. 30, 2013

Mar. 31, 2014

Sep. 30, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

In Thousands, unless otherwise specified

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Impaired [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Taken in Foreclosure [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Maximum [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Market Approach Valuation Technique [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Fair Value, Measurements, Nonrecurring [Member]

Acquisition Development And Construction [Member]

Commercial And Industrial [Member]

Commercial Real Estate [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Acquisition Development And Construction [Member]

Commercial Real Estate [Member]

Residential Mortgage [Member]

Mortgage Servicing Rights [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Significant Unobservable Inputs Level 3 [Member]

Acquisition Development And Construction [Member]

Commercial And Industrial [Member]

Commercial Real Estate [Member]

Acquisition Development And Construction [Member]

Commercial And Industrial [Member]

Commercial Real Estate [Member]

speed

Acquisition Development And Construction [Member]

Commercial Real Estate [Member]

Residential Mortgage [Member]

Mortgage Servicing Rights [Member]

Acquisition Development And Construction [Member]

Commercial Real Estate [Member]

Residential Mortgage [Member]

Mortgage Servicing Rights [Member]

speed

speed

Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loans, net

'

'

$4,254,200

$2,422,824

$3,359

$6,013

$2,462

'

$897

'

'

'

'

'

'

'

$8,388

$887

'

'

'

'

'

'

'

'

'

Fair Value Inputs, Comparability Adjustments

'

'

'

'

'

'

'

'

'

10.00%

9.00%

15.00%

30.00%

19.00%

36.00%

'

'

'

'

25.00%

20.00%

16.00%

9.30%

70.00%

37.00%

59.00%

12.80%

Fair Value Weighted Average

'

'

'

'

'

'

0.135

0.144

0.22

'

'

'

'

'

'

0.302

0.248

0.216

'

'

'

'

'

'

'

'

'

Prepayment speed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100

'

'

'

968

Weighted average prepayment speed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

224

'

'

'

'

'

'

'

'

Servicing Asset at Fair Value, Amount

$1,747

$1,978

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 4) (USD $)	Mar. 31, 2014	Sep. 30, 2013
Financial assets:	'	'
Securities available for sale	$1,233,310,000	$954,393,000
Securities held to maturity	527,121,000	250,896,000
Financial liabilities:	'	'
Senior Notes	-98,215,000	-98,033,000
Subordinated debentures	-26,509,000	0
Level 1 [Member]	'	'
Financial assets:	'	'
Cash and due from banks	164,645,000	113,090,000
Securities available for sale	0	0
Securities held to maturity	0	0
Loans, net	0	0
Loans held for sale	0	0
Accrued interest receivable on securities	0	0
Accrued interest receivable on loans	0	0
Interest rate caps and swaps	0	0
Financial liabilities:	'	'
Non-maturity deposits	-4,677,915,000	-2,694,166,000
Certificates of deposit	0	0
FHLB and other borrowings	0	0
Other Borrowings	0	'
Senior Notes	0	0
Subordinated debentures	0	'
Mortgage escrow funds	0	0
Accrued interest payable on deposits including escrow	0	0
Accrued interest payable on borrowings	0	0
Interest rate swaps	0	0
Level 2 [Member]	'	'
Financial assets:	'	'
Cash and due from banks	0	0
Securities available for sale	1,230,080,000	950,780,000
Securities held to maturity	527,121,000	250,896,000
Loans, net	0	0
Loans held for sale	21,348,000	1,011,000
Accrued interest receivable on securities	8,810,000	4,892,000
Accrued interest receivable on loans	0	0
Interest rate caps and swaps	756,000	997,000
Financial liabilities:	'	'
Non-maturity deposits	0	0
Certificates of deposit	-533,733,000	-268,088,000
FHLB and other borrowings	-511,976,000	-488,369,000
Other Borrowings	-19,992,000	'
Senior Notes	-100,947,000	-98,142,000
Subordinated debentures	-26,149,000	'
Mortgage escrow funds	-8,710,000	-12,644,000
Accrued interest payable on deposits including escrow	-427,000	-1,480,000
Accrued interest payable on borrowings	-2,736,000	'
Interest rate swaps	-756,000	-997,000
Level 3 [Member]	'	'
Financial assets:	'	'
Cash and due from banks	0	0
Securities available for sale	3,230,000	3,613,000
Securities held to maturity	0	0
Loans, net	4,254,200,000	2,422,824,000
Loans held for sale	0	0
Accrued interest receivable on securities	0	0
Accrued interest receivable on loans	9,344,000	'
Interest rate caps and swaps	0	0
Financial liabilities:	'	'
Non-maturity deposits	0	0
Certificates of deposit	0	0
FHLB and other borrowings	0	0
Other Borrowings	0	'
Senior Notes	0	0
Subordinated debentures	0	'
Mortgage escrow funds	0	0
Accrued interest payable on deposits including escrow	0	0
Accrued interest payable on borrowings	0	0
Interest rate swaps	0	0
Carrying Amount [Member]	'	'
Financial assets:	'	'
Cash and due from banks	164,645,000	113,090,000
Securities available for sale	1,233,310,000	954,393,000
Securities held to maturity	527,265,000	253,999,000
Loans, net	4,212,339,000	2,384,021,000
Loans held for sale	21,348,000	1,011,000
Accrued interest receivable on securities	8,810,000	4,892,000
Accrued interest receivable on loans	9,344,000	6,805,000
FHLB stock and Federal Reserve Bank stock	53,346,000	24,312,000
Interest rate caps and swaps	756,000	997,000
Financial liabilities:	'	'
Non-maturity deposits	-4,677,915,000	-2,694,166,000
Certificates of deposit	-533,809,000	-268,128,000
FHLB and other borrowings	-489,801,000	-462,953,000
Other Borrowings	-19,991,000	'
Senior Notes	-98,215,000	-98,033,000
Subordinated debentures	-26,509,000	'
Mortgage escrow funds	-8,711,000	-12,646,000
Accrued interest payable on deposits including escrow	-427,000	-1,480,000
Accrued interest payable on borrowings	-2,736,000	-1,525,000
Interest rate swaps	($756,000)	($997,000)

Recovered_Sheet2

Fair value measurements (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2013
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Available-for-sale Securities, Amortized Cost Basis	$1,243,027,000	'	$1,243,027,000	'	$973,709,000
Fair value	1,233,310,000	'	1,233,310,000	'	954,393,000
Changes in fair value recognized on provisions on loans held by the Company	'	'	-447,000	1,815,000	'
Mortgage servicing rights	1,747,000	'	1,747,000	'	1,978,000
Other real estate owned	9,275,000	'	9,275,000	'	6,022,000
Changes in fair value recognized through income for foreclosed assets held by the Company	0	158,000	224,000	606,000	'
Fair Value, Measurements, Recurring [Member]	'	'	'	'	'
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Loans	37,085,000	'	37,085,000	'	35,230,000
Fair Value, Measurements, Nonrecurring [Member]	'	'	'	'	'
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Other real estate owned	9,274,000	'	9,274,000	'	6,022,000
Level 3 [Member]	'	'	'	'	'
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Fair value	3,230,000	'	3,230,000	'	3,613,000
Loans	4,254,200,000	'	4,254,200,000	'	2,422,824,000
Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'	'
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	3,230,000	'	3,230,000	'	3,613,000
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Fair value	3,230,000	'	3,230,000	'	3,613,000
Mortgage-backed securities-residential [Member]	'	'	'	'	'
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Available-for-sale Securities, Amortized Cost Basis	594,425,000	'	594,425,000	'	454,173,000
Fair value	592,366,000	'	592,366,000	'	449,183,000
Mortgage-backed securities-residential [Member] | Collateralized Mortgage Obligations [Member]	'	'	'	'	'
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Available-for-sale Securities, Amortized Cost Basis	136,304,000	'	136,304,000	'	169,336,000
Fair value	134,851,000	'	134,851,000	'	166,654,000
Privately issued collateralized mortgage obligations [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'	'
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	3,230,000	'	3,230,000	'	3,613,000
Privately issued collateralized mortgage obligations [Member] | Basis points [Domain] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'	'
Mortgage-backed Securities Available-for-sale, Fair Value Disclosure	17	'	17	'	'
Commercial Real Estate [Member] | Taken in Foreclosure [Member] | Market Approach Valuation Technique [Member] | Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'	'	'	'
Fair Value Measurements (Textual) [Abstract]	'	'	'	'	'
Loans	$8,388,000	'	$8,388,000	'	'

Comprehensive_income_Details

Comprehensive income (Details) (USD $)

3 Months Ended

6 Months Ended

6 Months Ended

6 Months Ended

6 Months Ended

In Thousands, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Sep. 30, 2013

Mar. 31, 2014

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2012

Mar. 31, 2014

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2012

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Defined Benefit Plans Adjustment [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Accumulated Other Comprehensive Income (Loss) [Member]

Reclassification out of Accumulated Other Comprehensive Income [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income (Loss), Net of Tax

($14,285)

'

($14,285)

'

($15,330)

($11,126)

$8,474

($11,472)

$15,066

($3,159)

($7,555)

($3,858)

($8,167)

($14,285)

$919

($15,330)

$6,899

Other Comprehensive Income (Loss), before Reclassifications, Net of Tax

'

'

'

'

'

10

-4,446

'

'

0

0

'

'

10

-4,446

'

'

Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax

'

'

'

'

'

336

-2,146

'

'

699

612

'

'

1,035

-1,534

'

'

Other Comprehensive Income (Loss), Net of Tax

$5,241

($3,746)

$1,045

($5,980)

'

$346

($6,592)

'

'

$699

($612)

'

'

$1,045

($5,980)

'

'

Comprehensive_income_Details1

Comprehensive income (Details1) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]	'	'	'	'
Net gain (loss) on sale of securities	$60	$2,229	($585)	$3,645
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	34	1,324	-336	2,165
Income Tax Expense (Benefit)	-4,588	-2,203	2,361	-5,269
Net income	10,332	6,529	-3,671	13,549
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	'	'	-585	'
Income Tax Expense (Benefit)	'	'	-249	'
Net income	'	'	336	'
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]	'	'	'	'
Income Tax Expense (Benefit)	'	'	517	'
Net income	'	'	-699	'
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	'	'	($1,216)	'