Senior Notes, Secured, and Unsecured Indebtedness - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 39,764	$ 50,203	$ 60,645	$ 52,771
Restricted cash	0	504
Receivables	6,730	14,838
Escrow proceeds receivable	2,301	3,041
Real estate inventories	1,828,847	1,675,106
Investment in unconsolidated joint ventures	7,274	5,413
Goodwill	66,902	66,902
Intangibles, net	6,700	6,700
Deferred income taxes, net	79,846	79,726
Other assets, net	18,526	21,017
Investments in subsidiaries	0	0
Intercompany receivables	0	0
Total Assets	2,056,890	1,923,450
LIABILITIES AND EQUITY
Accounts payable	89,093	75,881
Accrued expenses	73,855	70,324
Notes payable	239,390	175,181
Total debt	1,167,170	1,105,776
Intercompany payables	0	0
Total liabilities	1,330,118	1,251,981
Equity
William Lyon Homes stockholders’ equity (deficit)	657,209	632,095
Noncontrolling interests	69,563	39,374
Total liabilities and equity	2,056,890	1,923,450
Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	10,692	14,066
5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	148,555	148,295
8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	422,872	422,896
7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	345,661	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	0	0
Deferred income taxes, net	0	0
Other assets, net	0	0
Investments in subsidiaries	657,209	632,095
Intercompany receivables	0	0
Total Assets	657,209	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)	657,209	632,095
Noncontrolling interests	0	0
Total liabilities and equity	657,209	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	34,723	44,332	52,607	48,462
Restricted cash	0	504
Receivables	2,810	8,986
Escrow proceeds receivable	887	2,020
Real estate inventories	945,690	922,990
Investment in unconsolidated joint ventures	7,124	5,263
Goodwill	14,209	14,209
Intangibles, net	0	0
Deferred income taxes, net	79,846	79,726
Other assets, net	17,056	18,980
Investments in subsidiaries	(26,354)	(34,522)
Intercompany receivables	0	0
Total Assets	1,075,991	1,062,488
LIABILITIES AND EQUITY
Accounts payable	63,320	45,065
Accrued expenses	68,725	62,167
Notes payable	98,481	80,915
Intercompany payables	175,165	170,757
Total liabilities	1,333,471	1,289,499
Equity
William Lyon Homes stockholders’ equity (deficit)	(257,480)	(227,011)
Noncontrolling interests	0	0
Total liabilities and equity	1,075,991	1,062,488
Reporting Entities | California Lyon | Subordinated amortizing notes
LIABILITIES AND EQUITY
Total debt	10,692	14,066
Reporting Entities | California Lyon | 5 3/4% Senior Notes due April 15, 2019
LIABILITIES AND EQUITY
Total debt	148,555	148,295
Reporting Entities | California Lyon | 8 1/2% Senior Notes due November 15, 2020
LIABILITIES AND EQUITY
Total debt	422,872	422,896
Reporting Entities | California Lyon | 7% Senior Notes due August 15, 2022
LIABILITIES AND EQUITY
Total debt	345,661	345,338
Reporting Entities | Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	563	2,723	764	573
Restricted cash	0	0
Receivables	680	937
Escrow proceeds receivable	1,414	1,021
Real estate inventories	631,365	589,762
Investment in unconsolidated joint ventures	150	150
Goodwill	52,693	52,693
Intangibles, net	6,700	6,700
Deferred income taxes, net	0	0
Other assets, net	1,176	1,738
Investments in subsidiaries	(592,218)	(561,546)
Intercompany receivables	245,506	239,248
Total Assets	348,029	333,426
LIABILITIES AND EQUITY
Accounts payable	20,533	27,807
Accrued expenses	5,025	8,059
Notes payable	0	0
Intercompany payables	0	0
Total liabilities	25,558	35,866
Equity
William Lyon Homes stockholders’ equity (deficit)	322,471	297,560
Noncontrolling interests	0	0
Total liabilities and equity	348,029	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	4,478	3,148	7,274	3,736
Restricted cash	0	0
Receivables	3,240	4,915
Escrow proceeds receivable	0	0
Real estate inventories	251,792	162,354
Investment in unconsolidated joint ventures	0	0
Goodwill	0	0
Intangibles, net	0	0
Deferred income taxes, net	0	0
Other assets, net	294	299
Investments in subsidiaries	0	0
Intercompany receivables	0	0
Total Assets	259,804	170,716
LIABILITIES AND EQUITY
Accounts payable	5,240	3,009
Accrued expenses	105	98
Notes payable	140,909	94,266
Intercompany payables	70,341	68,491
Total liabilities	216,595	165,864
Equity
William Lyon Homes stockholders’ equity (deficit)	(26,354)	(34,522)
Noncontrolling interests	69,563	39,374
Total liabilities and equity	259,804	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	0	0
Deferred income taxes, net	0	0
Other assets, net	0	0
Investments in subsidiaries	(38,637)	(36,027)
Intercompany receivables	(245,506)	(239,248)
Total Assets	(284,143)	(275,275)
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued expenses	0	0
Notes payable	0	0
Intercompany payables	(245,506)	(239,248)
Total liabilities	(245,506)	(239,248)
Equity
William Lyon Homes stockholders’ equity (deficit)	(38,637)	(36,027)
Noncontrolling interests	0	0
Total liabilities and equity	(284,143)	(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