Commitments and Contingencies (Tables)  | 
12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2016  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Commitments And Contingencies Disclosure [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary of Lease Exit Accruals | 
 A summary of the activity of these operating lease accruals consists of the following: 
 
 
 
 
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| Minimum Future Lease Payments for both Continuing and Discontinued Operations | 
 Minimum future lease payments for facility leases and future receipts from subleases as required under non-cancelable operating leases for both continuing and discontinued operations based on current interest rates in effect are as follows: 
 
 
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| Financial Covenants Related to Amended Subordination and Guaranty Agreement | 
 The required financial covenants related to certain lease agreements are as follows: 
 
 
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