Significant Accounting Policies Other Noncurrent Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Pension and other employee benefits	$ 148,384	$ 113,371
Future QF obligation, net	136,652	184,187
Environmental	30,189	30,127
Customer advances	34,681	41,020
Other	25,148	20,307
Total	$ 375,054	$ 389,012