Subsidiary Preferred Stock (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2014
Subsidiary preferred stock
Cash paid for redemption of preferred stock	$ 70,875
Series A Preferred Stock
Subsidiary preferred stock
Cash paid for redemption of preferred stock		$ 70,900
Subsidiary preferred stock, shares outstanding		75,000