Segments and Operations by Geographic Area Segments and Operations by Geographic Area (Reconciliation of Assets from Segment to Consolidated) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 2,407,934	$ 2,094,705	$ 1,655,800
Current assets of discontinued operations	18,591	30,608	43,100
Long-term assets of discontinued operations	7,648	121,695	104,000
Segment, Continuing Operations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 2,381,700	$ 1,942,400	$ 1,508,700