Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
State net operating loss carryforwards	$ 11,400	$ 11,336
Impairment losses	112,143	116,451
Prepaid income from land sales	5,490	5,507
Other	1,358	1,398
Total gross deferred tax assets	130,391	134,692
Valuation allowance	(6,012)	(6,176)
Total net deferred tax assets	124,379	128,516
Deferred tax liabilities:
Investment in real estate and property and equipment basis differences	3,071	2,484
Deferred gain on land sales and involuntary conversions	28,691	31,574
Installment sales	126,741	126,225
Pension Plan assets transferred to the 401(k) Plan	2,723	3,057
Total gross deferred tax liabilities	161,226	163,340
Net deferred tax liability	$ (36,847)	$ (34,824)