Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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Amount, after allowance for bad debt, of mortgage loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair Value - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value measurement gain/(loss)	$ 9,838		$ 5,824
Homebuilding [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes carrying value	597,220		597,066
Homebuilding [Member] \| Senior Notes due 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes carrying value	597,220		597,066
Homebuilding [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Senior Notes due 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes fair value	631,500		630,000
Mortgage Banking [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of mortgage loans held for sale	344,023		352,489
Mortgage Banking [Member] \| Level 2 [Member] \| Not Designated as Hedging Instrument [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustment income (expense)	4,014	$ (2,017)
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Rate Lock Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	778,931
Total fair value measurement gain/(loss)	9,324
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Forward Sales Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	1,046,318
Total fair value measurement gain/(loss)	(1,509)
Mortgage Banking [Member] \| Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Mortgages Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional or Principal Amount	342,000		350,558
Fair value of mortgage loans held for sale	344,023		352,489
Total fair value measurement gain/(loss)	$ 2,023		$ 1,931