Shareholders' Equity Shareholders' Equity (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Issuance of common shares	$ 4,756	$ 191,107
At-the-market equity issuance [Member]
Stock Issued During Period, Shares, New Issues	233,000
Issuance of common shares	$ 4,800
At-the-market equity issuance [Member] | Gross Proceeds [Member]
Issuance of common shares	$ 5,000