Accounting for the Impairment or Disposal of Long-Lived Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Discontinued Operations, Income Statement [Line Items]
Gain on property dispositions	$ 0	$ 38	$ 0	$ 46,292
Net income	0	133	0	48,276
Discontinued Operations [Member]
Discontinued Operations, Income Statement [Line Items]
Revenues	0	9	0	4,728
Operating expenses	0	86	0	(2,226)
Interest and other income	0	0	0	39
Interest expense	0	0	0	(557)
Depreciation and amortization	0	0	0	0
Income before gain on property dispositions	0	95	0	1,984
Gain on property dispositions	0	38	0	46,292
Net income	$ 0	$ 133	$ 0	$ 48,276