Stock-Related Benefit Plans - Additional Information (Detail)	12 Months Ended
Dec. 31, 2016 USD ($) Age $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant	9,646,760
Shares granted	2,805,652
Shares granted, weighted average grant date fair value \| $ / shares	$ 15.21
Unrecognized compensation cost relating to unvested restricted stock \| $	$ 77,400,000
Unrecognized compensation cost relating to unvested restricted stock, recognition period (in years)	2 years 10 months 24 days
Stock option outstanding	0	2,400	58,560
Intrinsic value of stock options outstanding and exercisable \| $		$ 0
Intrinsic values of options exercised \| $			$ 132,000
Stock options exercisable	0
Stock options exercised	0	0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted, vesting period	5 years
Compensation and benefits expense \| $	$ 32,700,000	$ 30,200,000	27,500,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation and benefits expense \| $	$ 0	$ 0	$ 0
Stock Incentive Plan Twenty Twelve \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	2,805,652	2,352,641	2,377,498
Shares granted, weighted average grant date fair value \| $ / shares	$ 15.21	$ 15.83	$ 16.79
Supplemental Executive Retirement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Trust held assets of Supplemental Executive Retirement Plan (SERP), shares	1,729,319	1,653,737
New York Community Bank
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of the ESOP Plan	All full-time employees who have attained 21 years of age and have completed twelve consecutive months of credited service are eligible to participate in the Employee Stock Ownership Plan ("ESOP"), with benefits vesting on a six-year basis,
Full-time employees, age to participate in plan \| Age	21
Shares granted, vesting period	6 years
Allocated shares to participants in the ESOP	617,031	552,829	560,228
ESOP-related compensation expense \| $	$ 9,800,000	$ 9,200,000	$ 8,800,000
New York Community Bank \| Third year of employment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested	20.00%
New York Community Bank \| Each successive year after third year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested	20.00%

Employee Stock Ownership Plan Qualifying Age

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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Number of common stock held in a trust that has been set up specifically to accumulate stock for the sole purpose of distribution to participating employees but not yet earned.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The amount of plan compensation cost recognized during the period.

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The shares or units in an ESOP trust that have been assigned to individual participant accounts based on a known formula. IRS rules require allocations to be nondiscriminatory generally based on compensation, length of service, or a combination of both. For any particular participant such shares or units may be vested, unvested, or partially vested.

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Description of the plan, including the basis for determining contributions, the employee groups covered, and the nature and effect of significant matters affecting comparability of information for all periods presented. For leveraged ESOPs and pension reversion ESOPs, the description generally includes the basis for releasing shares and how dividends on allocated and unallocated shares are used.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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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.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Number of options outstanding, including both vested and non-vested options.

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Percentage of vesting of share-based compensation awards.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Number of share options (or share units) exercised during the current period.

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