星空传媒 Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Narrative) (Details)

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