XML 21 R47.htm IDEA: XBRL DOCUMENT v2.3.0.15
BENEFIT PLANS: (Details) (USD $)
In Millions
9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
SCC Defined Benefit Pension Plans
  
Defined benefit plan, Net periodic benefit cost  
Interest cost$ 0.4$ 0.5
Expected return on plan assets(0.5)(0.5)
Amortization of net loss (gain)0.1 
SCC Post-retirement Health Care Plan
  
Defined benefit plan, Net periodic benefit cost  
Maximum amortization of net loss (gain) (0.1)
Maximum total periodic benefit cost0.10.1
Minera Mexico Pension Plans
  
Defined benefit plan, Net periodic benefit cost  
Interest cost0.51.2
Service cost0.81.5
Expected return on plan assets(2.5)(2.2)
Amortization of transition obligation (assets), net(0.1) 
Amortization of net loss (gain)(1.1)(0.7)
Amortization of prior services cost 0.1
Net periodic benefit costs(2.4)(0.1)
Minera Mexico Post-retirement Healthcare Plan
  
Defined benefit plan, Net periodic benefit cost  
Interest cost2.83.2
Service cost 0.3
Amortization of transition obligation (assets), net1.11.0
Amortization of net loss (gain) 0.1
Net periodic benefit costs$ 3.9$ 4.6