BUSINESS INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Business information
Total revenues	$ 114,517	$ 59,845
Total assets	350,435		443,463
Client
Business information
Number of clients	1
Revenue | Client
Business information
Concentration risk (as a percent)	19.00%
United States
Business information
Total revenues	97,905	51,387
Total assets	278,088		359,072
Rest of world
Business information
Total revenues	16,612	8,458
Total assets	$ 72,347		$ 84,391