Fair Value Fair Value (Private Equity Level 3 Fair Value Measurements) (Details) - Private Equity Technology Media and Telecommunications [Member] - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Quantitative information about Level 3 fair value measurements [Abstract]
Fair value	$ 12,447	$ 20,112
Marketability discount	30.00%
Discount rate		18.00%
Discount years		2 years
Minimum [Member]
Quantitative information about Level 3 fair value measurements [Abstract]
Revenue multiple	1.8	2.0
Maximum [Member]
Quantitative information about Level 3 fair value measurements [Abstract]
Revenue multiple	2.7	3.5