Investment Securities (Details 2) - Affiliated funds - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair value
Less than 12 months	$ 147,131	$ 66,858
12 months or longer	305	1,187
Total temporarily impaired securities	147,436	68,045
Unrealized losses
Less than 12 months	(9,204)	(5,362)
12 months or longer	(35)	(30)
Total Unrealized losses on temporarily impaired securities	$ (9,239)	$ (5,392)