Stockholders' Equity and EPS Common Stock Price per share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended	6 Months Ended
	May 19, 2014	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013
Common Stock Offering Price [Line Items]
Common stock offering price	$ 101
Net proceeds from public equity offering		$ 434,900	$ 434,866	$ 0
Common Stock
Common Stock Offering Price [Line Items]
Common stock issued in public offering (shares)			4,485,000