Equity Equity - Change in ownership of less-than-wholly-owned subsidiary (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Noncontrolling Interest [Line Items]
Net income	$ 6,011	$ (24,238)	$ 9,974	$ (25,256)
Net transfers to the noncontrolling interests			(8,189)
Change to the Company's total stockholders' equity from net income attributable to common stockholders and transfers to noncontrolling interests			3,246
Cumulative Net Income Attributable to Common Stockholders [Member]
Noncontrolling Interest [Line Items]
Net income			9,823
Net transfers to the noncontrolling interests
Additional Paid-in Capital [Member]
Noncontrolling Interest [Line Items]
Net income
Net decrease in the Company's additional paid-in capital for purchase of subsidiary partnership interests			(6,577)
Net transfers to the noncontrolling interests			$ (6,577)