Segment and Related Information (Reconciliation of Capital Expenditures) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	$ 52,060	$ 34,518	$ 26,591
Total Segments [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	49,700	31,500	24,700
Corporate [Member]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	$ 2,400	$ 3,000	$ 1,900