Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 59,746	$ 15,423
Restricted cash	21,972	14,246
Loans receivable, net	830,101	141,500
Loans held-for-sale, net	3,800
Loans receivable, at fair value	117,549
Investment in CT Legacy Asset, at fair value		132,000
Equity investments in unconsolidated subsidiaries	23,240	13,306
Accrued interest receivable, prepaid expenses and other assets	30,697	5,868
Total assets	1,087,105	322,343
Liabilities:
Accounts payable, accrued expenses and other liabilities	36,879	21,209
Secured notes	8,848	8,497
Repurchase obligations	165,239
Securitized debt obligations	74,472	139,184
Total liabilities	285,438	168,890
Equity:
Class A common stock, $0.10 par value, 100,000 shares authorized, 28,802 and 2,927 shares issued and outstanding as of June 30, 2013 and December 31, 2012, respectively	288	293
Additional paid-in capital	1,242,892	609,002
Accumulated deficit	(530,491)	(535,851)
Total Blackstone Mortgage Trust, Inc. stockholders' equity	712,689	73,444
Non-controlling interests	88,978	80,009
Total equity	801,667	153,453
Total liabilities and equity	1,087,105	322,343
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Loans receivable, net	77,000	141,500
Loans held-for-sale, net	3,800
Accrued interest receivable, prepaid expenses and other assets	2,838	4,021
Total assets	83,638	145,521
Liabilities:
Accounts payable, accrued expenses and other liabilities	155	88
Securitized debt obligations	74,472	139,184
Total liabilities	$ 74,627	$ 139,272