Commitments And Contingencies Colombia-Related Matters (Gain Contingencies) (Details) (Insurance recovery coverage suit [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2013 insurer
Insurance recovery coverage suit [Member]
Gain Contingencies [Line Items]
Initial number of primary general liability insurers involved in coverage suit	3
Number of primary insurers with which the company reached settlement agreements	3
Percent of defense costs in the ATA and ATS lawsuits to be paid by primary insurers	40.00%
Expense reimbursement received to date which is deferred in Other liabilities	$ 12