Fair Value Measurements - Amortized Cost and Estimated Fair Value of Available-For-Sale Marketable Securities (Detail) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Measurements Of Financial Instruments [Line Items]
Total available-for-sale marketable securities	$ 551,938	$ 519,943
Amortized Cost [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Total available-for-sale marketable securities	547,100	527,183
Amortized Cost [Member] \| Homebuilding [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Equity security	208,279	169,565
Debt securities	306,793	323,454
Total available-for-sale marketable securities	515,072	493,019
Amortized Cost [Member] \| Financial Services [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Total available-for-sale marketable securities	32,028	34,164
Fair Value [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Total available-for-sale marketable securities	551,938	519,943
Fair Value [Member] \| Homebuilding [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Equity security	208,818	160,021
Debt securities	310,647	325,413
Total available-for-sale marketable securities	519,465	485,434
Fair Value [Member] \| Financial Services [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Total available-for-sale marketable securities	$ 32,473	$ 34,509

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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- Definition

Amount of debt securities categorized neither as held-to-maturity nor trading.

+ References

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Amount of equity securities categorized neither as held-to-maturity nor as trading.

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+ Details