The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

+ References+ Details

Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References+ Details

- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References+ Details

Basis of Presentation (Details 3) (USD $) In Thousands, unless otherwise specified							6 Months Ended				6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Land [Member]	Dec. 31, 2011 Land [Member]	Jun. 30, 2012 Buildings and improvements [Member]	Dec. 31, 2011 Buildings and improvements [Member]	Jun. 30, 2012 Buildings and improvements [Member] Maximum [Member]	Jun. 30, 2012 Buildings and improvements [Member] Minimum [Member]	Jun. 30, 2012 Equipment [Member]	Dec. 31, 2011 Equipment [Member]	Jun. 30, 2012 Equipment [Member] Maximum [Member]	Jun. 30, 2012 Equipment [Member] Minimum [Member]
Property and equipment:
Total property and equipment, gross	$ 390,170	$ 385,227	$ 23,478	$ 23,451	$ 53,785	$ 53,322			$ 312,907	$ 308,454
Accumulated depreciation	(256,178)	(248,128)
Total property and equipment, net	$ 133,992	$ 137,099
Estimated Useful Lives							40 years	7 years			20 years	3 years