XML 76 R66.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Activity in Allowance for Losses on Covered Loans (Parenthetical) (Detail) - USD ($) $ in Millions | 6 Months Ended
--- | ---
Jun. 30, 2016 | Jun. 30, 2015
Am Trust Bank and Desert Hills Bank |  |
Valuation Allowance [Line Items] |  |
Allowance associated on loans acquired | $ 14.2 | $ 14.2

X
- Definition Amount of addition to allowance reserve for credit loss arising from purchase of loan and lease portfolios. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesLoansAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ValuationAllowanceLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=nyb_AmTrustBankAndDesertHillsBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |