EMPLOYEE BENEFIT PLANS - FUTURE BENEFITS EXPECTED TO BE PAID (DETAILS) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Qualified Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	$ 50.9
2013	61.1
2014	66.0
2015	76.5
2016	76.5
2017 to 2020	486.5
Nonqualified Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	2.2
2013	2.3
2014	2.4
2015	2.7
2016	2.8
2017 to 2020	16.6
Postretirement Medical Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	4.1
2013	4.7
2014	5.5
2015	6.4
2016	7.2
2017 to 2020	$ 47.8