Employee Benefit Benefits and Stock-Based Compensation - Outperform Stock Options (Details) - Outperform Stock Options	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares	Dec. 31, 2012 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value | $	$ 13,000,000	$ 19,000,000	$ 2,000,000
Unamortized compensation expense | $	$ 1,000,000
Weighted average period over which unamortized compensation cost will be recognized (in years)	7 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Expected Dividend Yield Rate			2.24%
Expected Life (in years)			3 years
Expected Correlation Factor			0.44
Theoretical Value			101.00%
Estimated Forfeiture Rate			15.00%
Fair value of OSO units awarded | $			$ 17,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding
Options outstanding, beginning (in shares) | shares	1,217,869.000000	2,148,865.000000	2,066,419
Options granted (in shares) | shares	0	0	748,481
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period | shares	(12,945)	(52,901)	(271,883)
Options expired (in shares) | shares	0	(106,844)	(286,924)
Options exercised (in shares) | shares	(589,944)	(771,251)	(107,228)
Options outstanding, ending (in shares) | shares	614,980.00000	1,217,869.000000	2,148,865.000000	2,066,419
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Options, Beginning, Initial Strike Price Per Unit, Minimum (in dollars per share)	$ 16.99	$ 14.1	$ 14.10
Options, Beginning, Initial Strike Price Per Unit, Maximum (in dollars per share)	27.53	36.60	36.60
Options, Beginning, Weighted Average Initial Strike Price (in dollars per share)	$ 22.76	$ 23.99	$ 23.40
Options, Beginning, Aggregate Intrinsic Value | $	$ 48,500,000	$ 88,000,000	$ 31,580,000.00	$ 6,600,000
OSO units Outstanding, Average Remaining Contractual Term	4 months 13 days	10 months 24 days	1 year 5 months 15 days	1 year 8 months 23 days
Options granted, Initial Strike Price Per Unit, Minimum (in dollars per share)	$ 0	$ 0	$ 20.29
Options granted, Initial Strike Price Per Unit, Maximum (in dollars per share)	0	0	26.69
Options granted, Weighted Average Initial Strike Price (in dollars per share)	0.00	0.00	22.64
Options forfeited, Initial Strike Price Per Unit, Minimum (in dollars per share)	20.29	16.99	14.10
Options forfeited, Initial Strike Price Per Unit, Maximum (in dollars per share)	26.69	27.53	36.60
Options forfeited, Weighted Average Initial Strike Price (in dollars per share)	22.81	22.99	22.33
Options expired, Initial Strke Price Per Unit, Minimum (in dollars per share)	0	36.6	16.35
Options expired, Initial Strke Price Per Unit, Maximum (in dollars per share)	0	36.6	24.30
Options expired, Weighted Average Initial Strike Price (in dollars per share)	0.00	36.60	21.48
Options exercised, Initial Strike Price Per Unit, Minimum (in dollars per share)	22.15	14.7	14.10
Options exercised, Initial Strike Price Per Unit, Maximum (in dollars per share)	22.97	27.53	14.10
Options exercised, Weighted Average Initial Strike Price (in dollars per share)	22.32	24.26	14.10
Options, Ending, Initial Strike Price Per Unit, Minimum (in dollars per share)	20.29	16.99	14.1	$ 14.10
Options, Ending, Initial Strike Price Per Unit, Maximum (in dollars per share)	26.69	27.53	36.60	36.60
Options, Ending, Weighted Average Initial Strike Price (in dollars per share)	$ 22.77	$ 22.76	$ 23.99	$ 23.40
On or After April 1, 2007
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Life of Award	3
Percent vested after three years	100.00%
S and P 500 Index
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Expected volatility rate			19.00%
Level 3 Communications, Inc.
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology
Expected volatility rate			39.00%
Performance Range 1
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Performance Qualifier to Index, Maximum	0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Success Multiplier of Pre Multiplier Gain	0.00
Performance Range 2
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Performance Qualifier to Index, Minimum	0.00%
Share-based Compensation Arrangement by Share-based Payment Award, Performance Qualifier to Index, Maximum	11.00%
Share-based Compensation Arrangement by Share-based Payment Award, Success Multiplier of Pre Multiplier Gain	0.36
Performance Range 3
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Performance Qualifier to Index, Minimum	11.00%
Share-based Compensation Arrangement by Share-based Payment Award, Success Multiplier of Pre Multiplier Gain	4.00