Subsequent Event (Details) - 1 months ended Jul. 31, 2015 - Subsequent Event [Member] - Regulus [Member] - USD ($) shares in Millions, $ in Millions	Total
Sale of Regulus' Common Stock [Abstract]
Number of shares of common stock sold (in shares)	2.7
Total proceeds from sale of common stock	$ 25.5
Gain from sale of common stock	$ 20.2