Fair Value Measurements - Fair Value of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warehouse receivables	$ 987,923	$ 1,342,468
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	52,828	48,776
Equity securities	78,547	153,762
Warehouse receivables and advance warehouse funding	1,364,630
Warehouse receivables		1,342,468
Total assets at fair value	1,496,005	1,545,006
Interest rate swaps		1,070
Securities sold, not yet purchased		3,133
Total liabilities at fair value		4,203
Recurring [Member] \| Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	6,818	3,138
Equity securities	78,547	153,762
Total assets at fair value	85,365	156,900
Securities sold, not yet purchased		3,133
Total liabilities at fair value		3,133
Recurring [Member] \| Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	46,010	45,638
Warehouse receivables and advance warehouse funding	1,364,630
Warehouse receivables		1,342,468
Total assets at fair value	1,410,640	1,388,106
Interest rate swaps		1,070
Total liabilities at fair value		1,070
Recurring [Member] \| U.S. treasury securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	6,818	3,138
Recurring [Member] \| U.S. treasury securities [Member] \| Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	6,818	3,138
Recurring [Member] \| Debt securities issued by U.S. federal agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	11,137	11,196
Recurring [Member] \| Debt securities issued by U.S. federal agencies [Member] \| Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	11,137	11,196
Recurring [Member] \| Corporate debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	27,463	27,201
Recurring [Member] \| Corporate debt securities [Member] \| Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	27,463	27,201
Recurring [Member] \| Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	5,159	5,017
Recurring [Member] \| Asset-backed securities [Member] \| Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	5,159	5,017
Recurring [Member] \| Collateralized mortgage obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	2,251	2,224
Recurring [Member] \| Collateralized mortgage obligations [Member] \| Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale debt securities	$ 2,251	$ 2,224

Loan receivable mortgage warehouse lending and advance warehouse funding current.

No definition available.

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- Definition

Reflects the gross carrying amount of unpaid loans pertaining to a revolving line of credit used by mortgage bankers in which the mortgage banker originates and purchases mortgage loans due within one year or the normal operating cycle, if longer.

+ References

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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-Section 50
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- 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
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- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
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- 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.

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- Definition

Fair value of obligations incurred from short sales.

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- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

No definition available.

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- Definition

Fair value of financial and nonfinancial obligations.

+ References

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