Other Assets - Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Identifiable intangible assets, net	$ 64,067	$ 75,736
Other financial receivables	41,003	37,861
Service fee receivables	31,782	25,609
Assets held for sale	26,241	18,741
Prepaid expenses	24,341	27,606
Deferred tax assets	14,376	18,773
Security deposits	2,947	3,451
Derivative instruments	2,450	5,834
Funds held in escrow	0	28,199
Prepaid income taxes	0	27,917
Other	37,395	33,001
Total	$ 244,602	$ 302,728