Quarterly report pursuant to Section 13 or 15(d)

Amortizable Intangible Assets - Summary of Significant Classes of Amortizable Intangible Assets (Detail)

v3.10.0.1
Amortizable Intangible Assets - Summary of Significant Classes of Amortizable Intangible Assets (Detail) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]    
Cost $ 64,444 $ 60,283
Accumulated Amortization (51,545) (47,179)
Net 12,899 13,104
Customer Lists and Contracts [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 24,673 22,865
Accumulated Amortization (21,498) (20,888)
Net 3,175 1,977
Domain and Brand Names [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 21,358 20,109
Accumulated Amortization (16,218) (14,650)
Net 5,140 5,459
Favorable and Assigned Leases [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 2,256 2,379
Accumulated Amortization (1,944) (2,028)
Net 312 351
Subscriber Base and Lists [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 9,672 8,797
Accumulated Amortization (6,548) (4,701)
Net 3,124 4,096
Author Relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 2,771 2,771
Accumulated Amortization (2,416) (2,237)
Net 355 534
Non-Compete Agreements [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 2,048 2,029
Accumulated Amortization (1,571) (1,342)
Net 477 687
Other Amortizable Intangible Assets [Member]    
Finite-Lived Intangible Assets [Line Items]    
Cost 1,666 1,333
Accumulated Amortization (1,350) $ (1,333)
Net $ 316