日韩三级片

Annual report pursuant to Section 13 and 15(d)

PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Narrative) (Details)

v3.6.0.2
PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Narrative) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items] 听 听
Minimum participants percentage 15.00% 听
Defined Benefit Plan, Accumulated Benefit Obligation $ 922,000,000 $ 898,900,000
Reserve for investment commitments $ 37,900,000 听
Structured Finance [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Redemption request notice period, days 90 days 听
Real Estate [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Redemption request notice period, days 45 days 听
Withdrawal request notice period, days 65 days 听
Pension Benefits [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Decrease in Projected Benefit Obligation due to Market Conditions $ 22,000,000 听
Reduction in net periodic benefit expense 8,200,000 听
Increase in Projected Benefit Obligation due to new mortality tables $ 13,100,000 听
Percentage Increase in Projected Benefit Obligation due to new mortality tables 1.40% 听
Participant contributions $ 0 0
Other Benefits [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Decrease in Projected Benefit Obligation due to Market Conditions 8,600,000 听
Reduction in net periodic benefit expense 1,800,000 听
Increase in Projected Benefit Obligation due to new mortality tables $ 4,900,000 听
Percentage Increase in Projected Benefit Obligation due to new mortality tables 2.00% 听
Participant contributions $ 6,000,000 $ 4,000,000
Tilden, Empire, Hibbing and United Taconite [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Percentage of total workforce covered by labor contract 80.00% 听
Prior To Age65 [Member] | Defined Benefit Postretirement Health Coverage [Member] | United States [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Annual limit on medical coverage for each participant $ 7,000 听
Prior To Age65 [Member] | Minimum [Member] | Defined Benefit Postretirement Health Coverage [Member] | Northshore [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Annual limit on medical coverage for each participant 4,020 听
Prior To Age65 [Member] | Maximum [Member] | Defined Benefit Postretirement Health Coverage [Member] | Northshore [Member] 听 听
Defined Benefit Plan Disclosure [Line Items] 听 听
Annual limit on medical coverage for each participant $ 4,500 听