Writedowns and Other Charges - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 13, 2015	Jun. 05, 2013
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of assets	$ 15,900,000
Net lease loss accrual	56,642,000	$ 8,625,000	$ 14,748,000
Senior Secured Notes
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of capitalized debt costs		9,600,000
Early principal payments		235,000,000
Senior Secured Notes | 8.25% Senior Secured Notes
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of capitalized debt costs	8,500,000
Payment of make whole premium	16,500,000
Aggregate principal amount	$ 305,000,000.0			$ 305,000,000	$ 305,000,000
Interest rate	8.25%				8.25%
Excess Real Estate Capacity
Writedown Of Asset And Lease Loss Accrual [Line Items]
Net lease loss accrual		$ 8,600,000	7,100,000
Leasehold Improvements and Fixed Assets
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of assets			$ 7,700,000
Jersey City and Chicago | Leasehold Improvements and Fixed Assets
Writedown Of Asset And Lease Loss Accrual [Line Items]
Writedown of fixed assets and loss from sale of microwave communication related assets	$ 17,000,000
Jersey, New York, Chicago and Greenwich | Early Lease Termination
Writedown Of Asset And Lease Loss Accrual [Line Items]
Early lease termination charges	$ 23,700,000