Goodwill and Intangible Assets - Summary of Intangible Assets from Continuing Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Asset impairment charges	$ 310	$ 117	$ 670	$ 348
Gross Carrying Amount	118,620		118,620		$ 118,756
Accumulated Amortization	(54,358)		(54,358)		(46,050)
Remaining amortization expense	64,262		64,262		72,706
Acquired Indefinite-lived Intangible Assets [Line Items]
Estimated salvage value of the asset	400		400		400
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	119,320		119,320		119,456
Accumulated Amortization	(54,358)		(54,358)		(46,050)
Net Carrying Amount	64,962		64,962		73,406
Other intellectual property
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets (excluding goodwill)	700		700		700
Internet domain names
Acquired Indefinite-lived Intangible Assets [Line Items]
Intangible assets (excluding goodwill)	300		300		300
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Asset impairment charges	300		300
Gross Carrying Amount	65,486		65,486		65,603
Accumulated Amortization	(26,573)		(26,573)		(21,783)
Remaining amortization expense	38,913		38,913		43,820
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(26,573)		$ (26,573)		$ (21,783)
Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			3 years		3 years
Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			11 years		11 years
Trademarks/trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22,904		$ 22,904		$ 22,904
Accumulated Amortization	(11,651)		(11,651)		(10,043)
Remaining amortization expense	11,253		11,253		12,861
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(11,651)		$ (11,651)		$ (10,043)
Trademarks/trade names | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			3 years		3 years
Trademarks/trade names | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			11 years		11 years
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,322		$ 26,322		$ 26,334
Accumulated Amortization	(12,538)		(12,538)		(10,675)
Remaining amortization expense	13,784		13,784		15,659
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(12,538)		$ (12,538)		$ (10,675)
Technology | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			5 years		5 years
Technology | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			9 years		9 years
Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,908		$ 3,908		$ 3,915
Accumulated Amortization	(3,596)		(3,596)		(3,549)
Remaining amortization expense	312		312		366
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	$ (3,596)		$ (3,596)		$ (3,549)
Non-compete agreements | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			3 years		3 years
Non-compete agreements | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful Life			5 years		5 years