Earnings Per Share (Earnings Allocable to Common Shares) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Class of Stock [Line Items]
Weighted average number of common shares, Basic and diluted (in shares)	[1]	77,060	85,497
Basic and diluted earnings per common share:
Net income (loss) attributable to iStar Inc. and allocable to common shareholders (in dollars per share)	[1]	$ (0.27)	$ (0.26)
Income (loss) attributable to iStar Inc. from continuing operations, Basic and diluted (in dollars per share)	[1],[2]	$ 0.00	$ (49.93)
Denominator for basic and diluted earnings per HPU share:
Weighted average High Performance Units outstanding for basic and diluted earnings per share (in shares)	[1],[2]	0	15
Common Stock
Class of Stock [Line Items]
Weighted average number of common shares, Basic and diluted (in shares)		77,060	85,497
Numerator for basic and diluted earnings per share:
Income (loss) from continuing operations attributable to iStar Inc. and allocable to common shareholders		$ (21,187)	$ (22,553)
Basic and diluted earnings per common share:
Net income (loss) attributable to iStar Inc. and allocable to common shareholders (in dollars per share)		$ (0.27)	$ (0.26)
HPU's
Basic and diluted earnings per common share:
Income (loss) attributable to iStar Inc. from continuing operations, Basic and diluted (in dollars per share)		$ 0.00	$ (49.93)
Numerator for basic and diluted earnings per HPU share:
Net income (loss) attributable to iStar Inc. and allocable to HPU holders		$ 0	$ (749)
Denominator for basic and diluted earnings per HPU share:
Weighted average High Performance Units outstanding for basic and diluted earnings per share (in shares)		0	15

[1] Income (loss) from continuing operations attributable to iStar Inc. was $(18.8) million and $(31.6) million for the three months ended March 31, 2016 and 2015, respectively. Refer to Note 15 for details on the calculation of earnings per share.

[2] All of the Company's outstanding High Performance Units ("HPUs") were repurchased and retired on August 13, 2015 (refer to Note 15)