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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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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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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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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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Fair Value - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value measurement gain/(loss)			$ 13,437		$ 5,824
Home Building [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes carrying value	$ 597,527		597,527		597,066
Home Building [Member] \| Senior Notes due 2022 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes carrying value	597,527		597,527		597,066
Home Building [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	624,000		624,000		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	322,944		322,944		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)	(1,986)	$ 1,572	7,613	$ 2,931
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	864,355		864,355
Total fair value measurement gain/(loss)			9,030
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	1,120,810		1,120,810
Total fair value measurement gain/(loss)			1,280
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	319,817		319,817		350,558
Fair value of mortgage loans held for sale	$ 322,944		322,944		352,489
Total fair value measurement gain/(loss)			$ 3,127		$ 1,931