Loans Receivable and Allowance for Loan Losses - Balances of Loans Receivable and Related Allowance for Loan Loss Allocation (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Loans:
Individually evaluated for impairment	$ 212,371	$ 213,663
Collectively evaluated for impairment	9,952,865	10,166,695
Loans receivable	10,165,236	10,380,358
Allowance for loan losses:
Individually evaluated for impairment	9,048	9,378
Collectively evaluated for impairment	73,452	76,722
Total allowance for loan losses	82,500	86,100	$ 94,200	$ 98,000
Consumer and Other Loans
Loans:
Individually evaluated for impairment	3,928	4,091
Collectively evaluated for impairment	221,899	235,023
Loans receivable	225,827	239,114
Allowance for loan losses:
Individually evaluated for impairment	286	310
Collectively evaluated for impairment	5,009	5,151
Total allowance for loan losses	5,295	5,461	6,434	6,288
Mortgage Loans \| Residential
Loans:
Individually evaluated for impairment	190,955	192,427
Collectively evaluated for impairment	5,023,815	5,172,936
Loans receivable	5,214,770	5,365,363
Allowance for loan losses:
Individually evaluated for impairment	8,691	9,044
Collectively evaluated for impairment	25,660	27,395
Total allowance for loan losses	34,351	36,439	44,378	44,951
Mortgage Loans \| Multi-Family
Loans:
Individually evaluated for impairment	6,059	7,112
Collectively evaluated for impairment	4,017,705	4,039,510
Loans receivable	4,023,764	4,046,622
Allowance for loan losses:
Individually evaluated for impairment	1	24
Collectively evaluated for impairment	33,948	34,877
Total allowance for loan losses	33,949	34,901	33,020	35,544
Mortgage Loans \| Commercial Real Estate
Loans:
Individually evaluated for impairment	11,429	10,033
Collectively evaluated for impairment	689,446	719,226
Loans receivable	700,875	729,259
Allowance for loan losses:
Individually evaluated for impairment	70	0
Collectively evaluated for impairment	8,835	9,299
Total allowance for loan losses	$ 8,905	$ 9,299	$ 10,368	$ 11,217

Financing Receivable, Allowance for Credit Losses, Evaluated for Impairment [Abstract]

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Financing Receivable, Evaluated for Impairment [Abstract]

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

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-Publisher FASB
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