XML 48 R38.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Summary of Amortized Cost of Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Available-for-Sale Debt Securities: |  |  |  |
Due within one year | [1] | $ 199,846 |  |
Due from one to five years | [1] | 1,283,154 |  |
Due from five to ten years | [1] | 1,359,372 |  |
Due after ten years | [1] | 1,280,511 |  |
Total debt securities available for sale |  | 4,122,883 | [1] | $ 3,531,427
Mortgage-Related Securities |  |  |  |
Available-for-Sale Debt Securities: |  |  |  |
Due from one to five years | [1] | 1,219,407 |  |
Due from five to ten years | [1] | 557,628 |  |
Due after ten years | [1] | 818,349 |  |
Total debt securities available for sale | [1] | $ 2,595,384 |  |
Available-for-Sale Debt Securities: |  |  |  |
Due from one to five years, Average Yield | [1] | 3.34% |  |
Due from five to ten years, Average Yield | [1] | 3.39% |  |
Due after ten years, Average Yield | [1] | 2.94% |  |
Total debt securities available for sale | [1] | 3.22% |  |
U.S. Treasury and GSE Obligations |  |  |  |
Available-for-Sale Debt Securities: |  |  |  |
Due within one year | [1] | $ 199,839 |  |
Due from one to five years | [1] | 6,950 |  |
Due from five to ten years | [1] | 471,325 |  |
Due after ten years | [1] | 84,591 |  |
Total debt securities available for sale | [1] | $ 762,705 |  |
Available-for-Sale Debt Securities: |  |  |  |
Due within one year, Average Yield | [1] | 1.70% |  |
Due from one to five years, Average Yield | [1] | 3.84% |  |
Due from five to ten years, Average Yield | [1] | 3.11% |  |
Due after ten years, Average Yield | [1] | 3.09% |  |
Total debt securities available for sale | [1] | 2.74% |  |
State, county, and municipal |  |  |  |
Available-for-Sale Debt Securities: |  |  |  |
Due within one year | [1] | $ 149 |  |
Due from one to five years | [1] | 293 |  |
Due after ten years | [1] | 69,104 |  |
Total debt securities available for sale | [1] | $ 69,546 |  |
Available-for-Sale Debt Securities: |  |  |  |
Due within one year, Average Yield | [1],[2] | 6.51% |  |
Due from one to five years, Average Yield | [1],[2] | 6.63% |  |
Due after ten years, Average Yield | [1],[2] | 2.88% |  |
Total debt securities available for sale | [1],[2] | 2.90% |  |
Other Debt Securities |  |  |  |
Available-for-Sale Debt Securities: |  |  |  |
Due from one to five years | [1],[3] | $ 48,648 |  |
Due from five to ten years | [1],[3] | 330,421 |  |
Due after ten years | [1],[3] | 329,007 |  |
Total debt securities available for sale | [1],[3] | $ 708,076 |  |
Available-for-Sale Debt Securities: |  |  |  |
Due from one to five years, Average Yield | [1] | 3.86% |  |
Due from five to ten years, Average Yield | [1] | 3.98% |  |
Due after ten years, Average Yield | [1] | 3.24% |  |
Total debt securities available for sale | [1] | 3.63% |  |
[1] | As equity securities have no contractual maturity, they have been excluded from this table.
[2] | Not presented on a tax-equivalent basis.
[3] | Includes corporate bonds, capital trust notes, and asset-backed securities.

X
- Definition Available for sale Securities, Debt Maturities, Average Yield + References No definition available. + Details
Name: | nyb_AvailableForSaleSecuritiesDebtMaturitiesAverageYield
Namespace Prefix: | nyb_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing after tenth rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Industry Guide -Number 3 -Section II -Paragraph B + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleMaturityRollingAfter10YearsWeightedAverageYield
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in sixth through tenth rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Industry Guide -Number 3 -Section II -Paragraph B + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleMaturityRollingAfterFiveThroughTenYearsWeightedAverageYield
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in second through fifth rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Industry Guide -Number 3 -Section II -Paragraph B + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleMaturityRollingAfterOneThroughFiveYearsWeightedAverageYield
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average yield of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Industry Guide -Number 3 -Section II -Paragraph B + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleMaturityRollingWithinOneYearWeightedAverageYield
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRollingMaturityWeightedAverageYieldAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |