Impairments Impairments Fair Value Nonrecurring (Details) (Fair Value, Measurements, Nonrecurring, USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Long-lived assets held for use | Fair Value Measurement
Property, Plant and Equipment [Line Items]
Assets, fair value	$ 93,945	$ 14,801	$ 26,625
Long-lived assets held for use | Level 1
Property, Plant and Equipment [Line Items]
Assets, fair value	0	0	0
Long-lived assets held for use | Level 2
Property, Plant and Equipment [Line Items]
Assets, fair value	0	0	0
Long-lived assets held for use | Level 3
Property, Plant and Equipment [Line Items]
Assets, fair value	93,945	14,801	26,625
Long-lived assets sold during the year | Fair Value Measurement
Property, Plant and Equipment [Line Items]
Assets, fair value		96,099	30,342
Long-lived assets sold during the year | Level 1
Property, Plant and Equipment [Line Items]
Assets, fair value		0	0
Long-lived assets sold during the year | Level 2
Property, Plant and Equipment [Line Items]
Assets, fair value		0	0
Long-lived assets sold during the year | Level 3
Property, Plant and Equipment [Line Items]
Assets, fair value		$ 96,099	$ 30,342