Other Investments (Narrative) (Details)	1 Months Ended			3 Months Ended		6 Months Ended	7 Months Ended	12 Months Ended
	Jun. 30, 2015 USD ($)	Apr. 30, 2013 USD ($)	Jul. 31, 2010 USD ($)	Jun. 30, 2013 USD ($)	Mar. 31, 2013 USD ($)	Dec. 31, 2013 USD ($)	Apr. 19, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) Investee lease_asset property	Dec. 31, 2013 USD ($)	Sep. 30, 2012 USD ($)	Apr. 30, 2014 USD ($)	Feb. 28, 2014 USD ($)	Jul. 28, 2010 USD ($)
Schedule of Equity Method Investments [Line Items]
Carrying Value								$ 254,172,000	$ 354,119,000
Earnings (loss) from equity method investments								32,153,000	94,905,000	$ 41,520,000
Income from sales of real estate								93,816,000	89,943,000	86,658,000
Distributions from other investments								119,854,000	61,031,000	36,918,000
Net proceeds from sales of real estate								362,530,000	404,336,000	437,817,000
Contributions to other investments								11,531,000	159,424,000	12,784,000
Provision for (recovery of) loan losses								36,567,000	(1,714,000)	5,489,000
Proceeds from sale of available-for-sale securities								7,400,000
Available-for-sale securities, realized gain								2,600,000
Interest income								134,687,000	122,704,000	108,015,000
Distributions from operations of other investments								29,999,000	80,116,000	17,252,000
Net Lease Asset One
Schedule of Equity Method Investments [Line Items]
Net proceeds from sales of real estate									$ 7,800,000
Land
Schedule of Equity Method Investments [Line Items]
Income from sales of real estate										600,000
Number of properties acquired | property									1
Operating Properties
Schedule of Equity Method Investments [Line Items]
Net proceeds from sales of real estate								93,500,000
Other real estate equity investments
Schedule of Equity Method Investments [Line Items]
Carrying Value								81,452,000	$ 88,848,000
Earnings (loss) from equity method investments								$ (5,212,000)	36,842,000	2,869,000
Other real estate equity investments | Minimum
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								31.00%
Other real estate equity investments | Maximum
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								70.00%
Other real estate equity investments | Land
Schedule of Equity Method Investments [Line Items]
Carrying Value								$ 16,600,000	13,800,000
Other real estate equity investments | Operating Properties
Schedule of Equity Method Investments [Line Items]
Carrying Value								11,100,000	13,200,000
iStar Net Lease I LLC
Schedule of Equity Method Investments [Line Items]
Carrying Value								69,096,000	125,360,000
Earnings (loss) from equity method investments								5,221,000	1,915,000	0
Distributions from other investments	$ 61,200,000
Total Revenue								31,315,000	13,826,000
Net income attributable to LNR								10,060,000	3,691,000
iStar Net Lease I LLC | Net Lease
Schedule of Equity Method Investments [Line Items]
Debt instrument, face amount	$ 120,000,000.0
iStar Net Lease I LLC | Net Lease
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage													51.90%
Partners' capital account, contributions (up to)													$ 500,000,000
Equity method investment, related party ownership percentage													0.60%
Equity method investment, related party promote fee percentage													50.00%
Equity method investment, partner ownership percentage													47.50%
Net proceeds from sales of real estate									$ 10,100,000
Noncontrolling interest, ownership percentage by parent									72.00%
Transfer mortgage payable									$ 26,000,000
Number of properties acquired | lease_asset									58
Acquisitions of real estate assets									$ 200,000,000
Total assets								400,200,000	348,100,000
Management fees revenue								1,500,000	1,300,000
iStar Net Lease I LLC | Net Lease Asset One
Schedule of Equity Method Investments [Line Items]
Net proceeds from sales of real estate									93,700,000
Other investments
Schedule of Equity Method Investments [Line Items]
Carrying Value								51,559,000	63,263,000
Earnings (loss) from equity method investments								9,434,000	38,385,000	23,810,000
Marina Palms
Schedule of Equity Method Investments [Line Items]
Carrying Value								30,099,000	30,677,000
Earnings (loss) from equity method investments								23,626,000	14,671,000	$ 45,000
iStar's ownership percentage						47.50%				47.50%
Income from sales of real estate										$ 3,400,000
Total Revenue								179,333,000	114,125,000	73,000
Net income attributable to LNR								63,749,000	37,005,000	(3,452,000)
Marina Palms | Land
Schedule of Equity Method Investments [Line Items]
Total assets								278,500,000	265,700,000
Net proceeds from sales of real estate										21,400,000
Madison Funds
Schedule of Equity Method Investments [Line Items]
Carrying Value								21,966,000	45,971,000
Earnings (loss) from equity method investments								$ (916,000)	3,092,000	$ 14,796,000
iStar's ownership percentage								29.50%
Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Earnings (loss) from equity method investments									$ 32,900,000
Equity Method Investee One
Schedule of Equity Method Investments [Line Items]
Equity method investee | Investee									1
Equity Method Investee Two
Schedule of Equity Method Investments [Line Items]
Earnings (loss) from equity method investments									$ 23,400,000
Equity Method Investee Two | Land
Schedule of Equity Method Investments [Line Items]
Carrying Value								$ 6,300,000	$ 9,400,000
iStar's ownership percentage									85.70%
Loans receivable, commitments, related party								45,700,000
Equity Method Investee Two | Land | Loans Receivable and Other Lending Investments, Net
Schedule of Equity Method Investments [Line Items]
Payments for funding under loan commitments								33,700,000
Equity method Investee Three
Schedule of Equity Method Investments [Line Items]
Equity method investee | Investee									1
Oak Hill Funds Group
Schedule of Equity Method Investments [Line Items]
Earnings (loss) from equity method investments								$ 2,200,000	$ 9,000,000
RCC | Operating Properties
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								50.00%
Distributions from other investments								$ 21,000,000
Sales price of real estate held for investment								68,500,000
Proceeds from sale of other real estate, net of equity contribution								55,400,000
Contributions to other investments								$ 13,600,000
RCC | Operating Properties
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								50.00%
Income from sales of real estate								$ 13,600,000
Sales price of real estate held for investment								68,500,000
Real Estate Equity Investment Three
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage						75.60%				75.60%
Real Estate Equity Investment Three | Net Lease
Schedule of Equity Method Investments [Line Items]
Earnings (loss) from equity method investments									$ 32,900,000
iStar's ownership percentage									50.00%
Proceeds from real estate and real estate joint ventures									$ 48,100,000
Real Estate Equity Investment Four | Land
Schedule of Equity Method Investments [Line Items]
Carrying Value								24,000,000	$ 23,500,000
iStar's ownership percentage									15.70%
Provision for (recovery of) loan losses									$ 2,800,000
Real Estate Equity Investment Five | Land
Schedule of Equity Method Investments [Line Items]
Carrying Value								13,500,000	21,100,000
iStar's ownership percentage						75.60%				75.60%
Real Estate Equity Investment Six | Land
Schedule of Equity Method Investments [Line Items]
Carrying Value								$ 9,900,000	7,800,000
iStar's ownership percentage						50.00%				50.00%
MIRELF III
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								32.90%
MIRELF III AIV
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								32.90%
Madison GP1 Investors LP
Schedule of Equity Method Investments [Line Items]
iStar's ownership percentage								29.50%
1000 SCI, LLC
Schedule of Equity Method Investments [Line Items]
Interest income								$ 3,900,000	600,000
Total Revenue								0
Net income attributable to LNR								$ (367,000)
LNR Property LLC
Schedule of Equity Method Investments [Line Items]
Earnings (loss) from equity method investments							$ 45,375,000			$ 16,500,000	$ 60,669,000
iStar's ownership percentage							24.00%				24.00%			24.00%
Ownership percentage acquired by entity														100.00%
Contribution towards principal amount debt extinguished			$ 100,000,000
Payments to acquire equity method investments			$ 100,000,000
Equity method investment, aggregate cost														$ 120,000,000
Net proceeds released from escrow												$ 25,200,000
Total Revenue							$ 179,373,000				$ 332,902,000
Income tax (expense) benefit							(2,137,000)				(6,731,000)
Net income attributable to LNR							113,478,000				253,039,000
Operating cash flows							(127,075,000)				(85,909,000)
Cash flows from investing activities							(36,543,000)				(55,686,000)
Cash flows from financing activities							217,241,000				229,634,000
Net cash flows							53,623,000				88,039,000
Cash distributions							0				61,179,000
Servicing fee revenue							55,500,000				95,400,000
Other loss				$ (66,200,000)
Carrying value of LNR at beginning of period		$ 220,281,000		220,281,000	$ 205,773,000	$ 0			$ 0	205,773,000
Equity in earnings of LNR for the period				0	45,375,000	0				45,375,000
Balance before other than temporary impairment				220,281,000	251,148,000	0				251,148,000
Other than temporary impairment				0	(30,867,000)	0				(30,867,000)
Sales proceeds pursuant to contract		$ (220,300,000)		(220,281,000)	0	0				(220,281,000)
Carrying value of LNR at end of period				$ 0	$ 220,281,000	$ 0				0
Income (loss) from equity method investments, release of AOCI										$ 1,700,000
Distributions from operations of other investments							$ 0				$ 14,690,000