Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents	$ 1,746,948	$ 1,992,497
Cash Held by Blackstone Funds and Other	703,182	1,929,531
Restricted Cash included in Other Assets	0	14,461
Cash and Cash Equivalents, Cash Held by Blackstone Funds and Other, and Restricted Cash	$ 2,450,130	$ 3,936,489