Discontinued Operations and Assets and Liabilities Held-for-Sale - Income Statement and Balance Sheet disclosures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income from discontinued operations, net of tax	$ 4,434	$ 1,688	$ 8,322	$ 1,484
Loss on sale or impairment loss on classification of assets as held-for-sale, net of tax	(4,257)	(10)	(11,403)	(1,859)
Net income (loss) from discontinued operations, net of tax	177	1,678	(3,081)	(375)
Real estate assets held-for-sale:
Cash and cash equivalents	30,510	33,279	30,510	33,279
Assets held-for-sale	432,894		432,894		$ 440,689
Real estate liabilities held-for-sale:
Liabilities held-for-sale	210,352		210,352		207,566
Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	113,290	82,859	208,237	151,112
Other	38	22	486	49
Cost of sales and expenses	107,817	81,127	198,411	149,544
General, administrative, and other	10,158	7,468	18,373	14,935
Sales and marketing	6,219	4,666	11,368	9,096
Impairment loss on long-lived assets		2,397	102	2,397
Income before income taxes	5,473	1,732	9,826	1,568
Provision for federal and state income taxes	969		1,491
Net income from discontinued operations, net of tax	4,434	1,688	8,322	1,484	13,899	$ (24,310)	$ (23,700)
Loss on sale or impairment loss on classification of assets as held-for-sale, net of tax	(4,257)		11,405		(1,775)	(18,729)
Net income (loss) from discontinued operations, net of tax	177	1,678	(3,081)	(375)	12,124	$ (43,039)	$ (23,700)
Net (income) loss from discontinued operations attributable to noncontrolling interests	(1,405)	(680)	2,796	620
Net income (loss) from discontinued operations attributable to PICO Holdings, Inc.	(1,228)	998	(5,877)	(995)
Real estate assets held-for-sale:
Assets held-for-sale	432,894		432,894		440,689
Real estate liabilities held-for-sale:
Liabilities held-for-sale	210,352		210,352		207,566
Real Estate Operations | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	113,252	82,837	207,751	151,063
Cost of sales and expenses	91,440	66,596	168,568	123,116
Net income from discontinued operations, net of tax	4,504	1,732	8,335	1,568
Real estate assets held-for-sale:
Cash and cash equivalents	30,510		30,510		40,931
Real estate	392,347		392,347		373,207
Accounts receivable	6,962		6,962		5,628
Other assets	14,290		14,290		14,418
Valuation allowance on assets held-for-sale	(11,215)		(11,215)
Assets held-for-sale	432,894		432,894		434,184
Real estate liabilities held-for-sale:
Debt, net	159,565		159,565		160,994
Account payable and accrued expenses	35,294		35,294		34,025
Other liabilities	15,493		15,493		12,271
Liabilities held-for-sale	210,352		210,352		207,290
Agribusiness Operations | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income from discontinued operations, net of tax	(70)	(44)	(13)	(84)
Income (loss) on sale of discontinued agribusiness operations, net of tax		$ (10)	2	$ (1,859)
Real estate assets held-for-sale:
Assets held-for-sale					6,505
Real estate liabilities held-for-sale:
Liabilities held-for-sale					$ 276