Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 70,834	$ 52,342
Restricted cash	10,677	10,096
Loans receivable, net	2,710,159	2,047,223
Equity investments in unconsolidated subsidiaries	23,394	22,480
Accrued interest receivable, prepaid expenses, and other assets	79,323	80,639
Total assets	2,894,387	2,212,780
Liabilities and equity
Accounts payable, accrued expenses, and other liabilities	66,711	56,972
Repurchase obligations	1,529,788	1,109,353
Convertible notes, net	160,094	159,524
Securitized debt obligations	39,394	40,181
Participations sold	90,000	90,000
Total liabilities	1,885,987	1,456,030
Equity
Common Stock	387	288
Additional paid-in capital	1,510,860	1,252,986
Accumulated other comprehensive income	834	798
Accumulated deficit	(542,004)	(536,170)
Total Blackstone Mortgage Trust, Inc. stockholders' equity	970,083	717,909
Non-controlling interests	38,317	38,841
Total equity	1,008,400	756,750
Total liabilities and equity	2,894,387	2,212,780
Restricted Class A Common Stock [Member]
Equity
Common Stock	$ 6	$ 7