Property and Equipment (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Retirement of Tangible Assets, Other Descriptors	$ 6,332
Depreciation	$ 20,891	$ 20,739	$ 19,805