Property, Plant And Equipment (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2012 Property, Plant And Equipment [Member]	Jun. 30, 2011 Property, Plant And Equipment [Member]	Jun. 30, 2012 Property, Plant And Equipment [Member]	Jun. 30, 2011 Property, Plant And Equipment [Member]
Pieces of land acquired			4
Useful life of finite intangible asset	50 years
Depreciation and amortization expense	$ 3,605	$ 3,286		$ 1,200	$ 1,300	$ 2,300	$ 2,000