Senior Notes, Secured, and Unsecured Indebtedness - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 35,798	$ 50,203	$ 29,450	$ 52,771
Restricted cash	505	504
Receivables	6,124	14,838
Escrow proceeds receivable	3,024	3,041
Real estate inventories	1,753,315	1,675,106
Investment in unconsolidated joint ventures	6,414	5,413
Goodwill	66,902	66,902
Intangibles, net of accumulated amortization of $4,640 as of March 31, 2016 and December 31, 2015	6,700	6,700
Deferred income taxes, net	79,631	79,726
Other assets, net	20,622	21,017
Investments in subsidiaries	0	0
Intercompany receivables	0	0
Total assets	1,979,035	1,923,450
LIABILITIES AND EQUITY
Accounts payable	78,854	75,881
Accrued expenses	71,576	70,324
Notes payable	185,817	175,181
Intercompany payables	0	0
Total liabilities	1,265,427	1,251,981
Equity
William Lyon Homes stockholders’ equity (deficit)	641,531	632,095
Noncontrolling interests	72,077	39,374
Total liabilities and equity	1,979,035	1,923,450
Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	12,390	14,066
5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	148,429	148,295
8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	422,887	422,896
7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	345,474	345,338
Reporting Entities | Delaware Lyon
ASSETS
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Receivables	0	0
Escrow proceeds receivable	0	0
Real estate inventories	0	0
Investment in unconsolidated joint ventures	0	0
Goodwill	0	0
Intangibles, net of accumulated amortization of $4,640 as of March 31, 2016 and December 31, 2015	0	0
Deferred income taxes, net	0	0
Other assets, net	0	0
Investments in subsidiaries	641,531	632,095
Intercompany receivables	0	0
Total assets	641,531	632,095
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued expenses	0	0
Notes payable	0	0
Intercompany payables	0	0
Total liabilities	0	0
Equity
William Lyon Homes stockholders’ equity (deficit)	641,531	632,095
Noncontrolling interests	0	0
Total liabilities and equity	641,531	632,095
Reporting Entities | Delaware Lyon | Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Delaware Lyon | 5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Delaware Lyon | 8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Delaware Lyon | 7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | California Lyon
ASSETS
Cash and cash equivalents	30,178	44,332	26,659	48,462
Restricted cash	505	504
Receivables	2,261	8,986
Escrow proceeds receivable	0	2,020
Real estate inventories	898,212	922,990
Investment in unconsolidated joint ventures	6,264	5,263
Goodwill	14,209	14,209
Intangibles, net of accumulated amortization of $4,640 as of March 31, 2016 and December 31, 2015	0	0
Deferred income taxes, net	79,631	79,726
Other assets, net	18,610	18,980
Investments in subsidiaries	(25,858)	(34,522)
Intercompany receivables	0	0
Total assets	1,024,012	1,062,488
LIABILITIES AND EQUITY
Accounts payable	54,077	45,065
Accrued expenses	67,200	62,167
Notes payable	62,201	80,915
Intercompany payables	171,819	170,757
Total liabilities	1,284,477	1,289,499
Equity
William Lyon Homes stockholders’ equity (deficit)	(260,465)	(227,011)
Noncontrolling interests	0	0
Total liabilities and equity	1,024,012	1,062,488
Reporting Entities | California Lyon | Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	12,390	14,066
Reporting Entities | California Lyon | 5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	148,429	148,295
Reporting Entities | California Lyon | 8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	422,887	422,896
Reporting Entities | California Lyon | 7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	345,474	345,338
Reporting Entities | Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	194	2,723	380	573
Restricted cash	0	0
Receivables	624	937
Escrow proceeds receivable	3,024	1,021
Real estate inventories	620,678	589,762
Investment in unconsolidated joint ventures	150	150
Goodwill	52,693	52,693
Intangibles, net of accumulated amortization of $4,640 as of March 31, 2016 and December 31, 2015	6,700	6,700
Deferred income taxes, net	0	0
Other assets, net	1,708	1,738
Investments in subsidiaries	(597,916)	(561,546)
Intercompany receivables	241,527	239,248
Total assets	329,382	333,426
LIABILITIES AND EQUITY
Accounts payable	21,037	27,807
Accrued expenses	4,265	8,059
Notes payable	0	0
Intercompany payables	0	0
Total liabilities	25,302	35,866
Equity
William Lyon Homes stockholders’ equity (deficit)	304,080	297,560
Noncontrolling interests	0	0
Total liabilities and equity	329,382	333,426
Reporting Entities | Guarantor Subsidiaries | Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Guarantor Subsidiaries | 5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Guarantor Subsidiaries | 8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Guarantor Subsidiaries | 7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Non-Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	5,426	3,148	2,411	3,736
Restricted cash	0	0
Receivables	3,239	4,915
Escrow proceeds receivable	0	0
Real estate inventories	234,425	162,354
Investment in unconsolidated joint ventures	0	0
Goodwill	0	0
Intangibles, net of accumulated amortization of $4,640 as of March 31, 2016 and December 31, 2015	0	0
Deferred income taxes, net	0	0
Other assets, net	304	299
Investments in subsidiaries	0	0
Intercompany receivables	0	0
Total assets	243,394	170,716
LIABILITIES AND EQUITY
Accounts payable	3,740	3,009
Accrued expenses	111	98
Notes payable	123,616	94,266
Intercompany payables	69,708	68,491
Total liabilities	197,175	165,864
Equity
William Lyon Homes stockholders’ equity (deficit)	(25,858)	(34,522)
Noncontrolling interests	72,077	39,374
Total liabilities and equity	243,394	170,716
Reporting Entities | Non-Guarantor Subsidiaries | Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Non-Guarantor Subsidiaries | 5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Non-Guarantor Subsidiaries | 8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	0	0
Reporting Entities | Non-Guarantor Subsidiaries | 7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	0	0
Consolidation, Eliminations
ASSETS
Cash and cash equivalents	0	0	$ 0	$ 0
Restricted cash	0	0
Receivables	0	0
Escrow proceeds receivable	0	0
Real estate inventories	0	0
Investment in unconsolidated joint ventures	0	0
Goodwill	0	0
Intangibles, net of accumulated amortization of $4,640 as of March 31, 2016 and December 31, 2015	0	0
Deferred income taxes, net	0	0
Other assets, net	0	0
Investments in subsidiaries	(17,757)	(36,027)
Intercompany receivables	(241,527)	(239,248)
Total assets	(259,284)	(275,275)
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued expenses	0	0
Notes payable	0	0
Intercompany payables	(241,527)	(239,248)
Total liabilities	(241,527)	(239,248)
Equity
William Lyon Homes stockholders’ equity (deficit)	(17,757)	(36,027)
Noncontrolling interests	0	0
Total liabilities and equity	(259,284)	(275,275)
Consolidation, Eliminations | Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	0	0
Consolidation, Eliminations | 5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	0	0
Consolidation, Eliminations | 8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	0	0
Consolidation, Eliminations | 7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	$ 0	$ 0