Discontinued Operations and Assets and Liabilities Held-for-Sale - Results from Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Cost of sales and expenses from discontinued real estate operations:
Net income from discontinued operations, net of tax		$ 4,434		$ 8,322
Income (loss) on sale of discontinued operation	43	(4,257)	43	(11,403)
Net income (loss) from discontinued operations, net of tax	43	177	43	(3,081)
Net income from discontinued operations attributable to noncontrolling interests		(1,405)		(2,796)
Net income (loss) from discontinued operations attributable to PICO Holdings, Inc.	43	(1,228)	43	(5,877)
Real Estate Operations
Revenue and other income from discontinued real estate operations:
Sales of real estate		113,252		207,751
Other		38		486
Total revenue and other income		113,290		208,237
Cost of sales and expenses from discontinued real estate operations:
Cost of real estate sold		91,440		168,568
General, administrative, and other		10,158		18,373
Sales and marketing		6,219		11,368
Impairment loss on long-lived assets				102
Total cost of sales and expenses		107,817		198,411
Income before income taxes		5,473		9,826
Provision for federal and state income taxes		(969)		(1,491)
Net income from discontinued operations, net of tax		4,504		8,335
Income (loss) on sale of discontinued operation	43	(4,257)	43	(11,405)
Agribusiness Operations
Cost of sales and expenses from discontinued real estate operations:
Net income from discontinued operations, net of tax		(70)		(13)
Income (loss) on sale of discontinued operation				$ 2