Earnings Per Share (Schedule of Earnings Per Share) (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Numerator for basic earnings per share:
Gain from discontinued operations	$ 0		$ 9,166		$ 0		$ 22,488
Denominator for basic and diluted earnings per share:
Basic	85,163	[1]	85,392	[1]	84,967	[1]	85,116	[1]
Diluted	130,160	[1]	85,392	[1]	84,967	[1]	85,116	[1]
Basic earnings per share:
Basic	$ 0.26	[1]	$ (0.46)	[1]	$ (0.24)	[1]	$ (1.43)	[1]
Earnings Per Share, Basic	$ 0.26	[1]	$ (0.36)	[1]	$ (0.24)	[1]	$ (1.15)	[1]
Diluted earnings per share:
Income (loss) from continuing operations	$ 0.21	[1]	$ (0.46)	[1]	$ (0.24)	[1]	$ (1.43)	[1]
Earnings Per Share, Diluted	$ 0.21	[1]	$ (0.36)	[1]	$ (0.24)	[1]	$ (1.15)	[1]
Common Stock
Denominator for basic and diluted earnings per share:
Basic	85,163		85,392		84,967		85,116
Add: Effect of assumed shares issued under treasury stock method for restricted shares	505		0		0		0
Diluted	130,160		85,392		84,967		85,116
Basic earnings per share:
Basic	$ 0.26		$ (0.46)		$ (0.24)		$ (1.43)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$ 0.00		$ 0.00		$ 0.00		$ 0.02
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Basic Share	$ 0.00		$ 0.10		$ 0.00		$ 0.26
Earnings Per Share, Basic	$ 0.26		$ (0.36)		$ (0.24)		$ (1.15)
Diluted earnings per share:
Income (loss) from continuing operations	$ 0.21		$ (0.46)		$ (0.24)		$ (1.43)
Income (loss) from discontinued operations	$ 0.00		$ 0.00		$ 0.00		$ 0.02
Gain from discontinued operations	$ 0.00		$ 0.10		$ 0.00		$ 0.26
Earnings Per Share, Diluted	$ 0.21		$ (0.36)		$ (0.24)		$ (1.15)
HPU's
Denominator for basic and diluted earnings per share:
Weighted average High Performance Units outstanding for basic and diluted earnings per share	15		15		15		15
Joint venture shares | Common Stock
Denominator for basic and diluted earnings per share:
Add: Effect of joint venture shares	298		0		0		0
3.00% convertible senior unsecured notes | Common Stock
Denominator for basic and diluted earnings per share:
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	16,992		0		0		0
1.50% convertible senior unsecured notes | Common Stock
Denominator for basic and diluted earnings per share:
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	11,567		0		0		0
Series J convertible perpetual preferred stock | Common Stock
Denominator for basic and diluted earnings per share:
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	15,635		0		0		0
Basic | Common Stock
Numerator for basic earnings per share:
Income (loss) from continuing operations attributable to iStar Financial Inc. and allocable to common shareholders	22,327		(39,689)		(20,454)		(120,995)
Income (loss) from discontinued operations	0		247		0		1,394
Gain from discontinued operations	0		8,871		0		21,762
Net Income (Loss) Attributable to Parent and Available to Common Shareholders	22,327		(30,571)		(20,454)		(97,839)
Basic | HPU's
Numerator for basic earnings per share:
Income (loss) from continuing operations attributable to iStar Financial Inc. and allocable to HPU holders	744		(1,319)		(683)		(4,036)
Income (loss) from discontinued operations	0		8		0		47
Gain from discontinued operations	0		295		0		726
Net Income (Loss) Attributable to Parent and Available to HPU Holders	744		(1,016)		(683)		(3,263)
Basic earnings per share:
Basic	$ 49.60		$ (87.93)		$ (45.53)		$ (269.07)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$ 0.00		$ 0.53		$ 0.00		$ 3.13
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Basic Share	$ 0.00		$ 19.67		$ 0.00		$ 48.40
Earnings Per Share, Basic	$ 49.60		$ (67.73)		$ (45.53)		$ (217.54)
Diluted | Common Stock
Numerator for basic earnings per share:
Income (loss) from continuing operations attributable to iStar Financial Inc. and allocable to common shareholders	27,608		(39,689)		(20,454)		(120,995)
Income (loss) from discontinued operations	0		247		0		1,394
Gain from discontinued operations	0		8,871		0		21,762
Net Income (Loss) Attributable to Parent and Available to Common Shareholders	27,608		(30,571)		(20,454)		(97,839)
Diluted | HPU's
Numerator for basic earnings per share:
Income (loss) from continuing operations attributable to iStar Financial Inc. and allocable to HPU holders	602		(1,319)		(683)		(4,036)
Income (loss) from discontinued operations	0		8		0		47
Gain from discontinued operations	0		295		0		726
Net Income (Loss) Attributable to Parent and Available to HPU Holders	$ 602		$ (1,016)		$ (683)		$ (3,263)
Diluted earnings per share:
Income (loss) from continuing operations	$ 40.13		$ (87.93)		$ (45.53)		$ (269.07)
Income (loss) from discontinued operations	$ 0.00		$ 0.53		$ 0.00		$ 3.13
Gain from discontinued operations	$ 0.00		$ 19.67		$ 0.00		$ 48.40
Earnings Per Share, Diluted	$ 40.13		$ (67.73)		$ (45.53)		$ (217.54)

[1] Income (loss) from continuing operations attributable to iStar Financial Inc. was $8.1 million and $(44.1) million for the three and nine months ended September 30, 2014, respectively, and $(42.3) million and $(160.9) million for the three and nine months ended September 30, 2013, respectively. See Note 13 for details on the calculation of earnings per share.