Commitments and Contingencies - Narrative (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 25, 2016 USD ($)	Dec. 31, 2015 USD ($) employee collective_bargaining_agreement	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Loss Contingencies [Line Items]
Rent expense for operating leases and other rental items		$ 122,000	$ 118,400	$ 118,600
Sublease rental income		$ 1,200	1,300	1,200
Number of collective bargaining agreements that are national or regional in scope | collective_bargaining_agreement		2
Restructuring expenses		$ 824	1,168	647
Restructuring reserve		$ 81	281	194
Settlement agreement terms		Under the terms of the consent decree, USM will (a) pay an aggregate of $1.0 million (i) for monetary relief to the members of the class, (ii) for awards to the class representative plaintiffs, (iii) for California Labor Code Private Attorney General Act payments to the State of California for an immaterial amount, and (iv) for all costs of notice and administration of the claims process, (b) pay to counsel for the class an aggregate of $1.3 million, of which $0.2 million has been allocated for their reimbursable costs and litigation expenses and $1.1 million has been allocated for attorneys’ fees, and (c) monitor USM’s California subcontractors providing janitorial services to its Customer in accordance with agreed upon procedures designed principally to ensure janitorial employees of those subcontractors are paid no less than minimum wage.
Minimum
Loss Contingencies [Line Items]
Number of employees | employee		29,000
Number of collective bargaining agreements between our individual subsidiaries and local unions | collective_bargaining_agreement		375
Surety Bond [Member]
Loss Contingencies [Line Items]
Aggregate estimated exposure		$ 1,200,000
Class Action Aggregate Monetary Portion [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		1,000
Payments for legal settlements		1,000
Class Action Aggregate Counsel Portion [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		1,300
Class Action Litigation Expenses [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		200
Class Action Attorney Fees [Member]
Loss Contingencies [Line Items]
Litigation settlement amount		1,100
Employee Severance [Member]
Loss Contingencies [Line Items]
Restructuring expenses		930	600	500
Facility Closing [Member]
Loss Contingencies [Line Items]
Restructuring expenses			$ 600	$ 100
Reversal of restructuring expenses		$ (106)
Unionized Employees Concentration Risk [Member] | Workforce Subject to Collective Bargaining Arrangements [Member]
Loss Contingencies [Line Items]
Percentage of employees represented by unions		56.00%
Subsequent Event [Member] | Class Action Aggregate Counsel Portion [Member]
Loss Contingencies [Line Items]
Payments for legal settlements	$ 1,300