Leases - Schedule of Transitions to ASC 842 on Condensed Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands		Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Line Items]
Prepaid expenses		$ 8,381		$ 7,771	[1]
Right of use asset		43,389
Deferred income tax assets, net		74,850		81,628
Assets of discontinued operations, non-current		178		178
Lease liability - operating, current		14,595
Other accrued expenses, current		10,277		19,668	[1]
Liabilities of discontinued operations, current		8		536
Lease liability - operating, non-current		47,328
Deferred rent obligations	[1]			12,745
Other liabilities, non-current		9,885		17,493	[1]
Accumulated deficit		$ (27,120)		$ (52,946)	[2]
ASC 842 [Member]
Leases [Line Items]
Prepaid expenses	[1]		$ 6,269
Right of use asset			45,963
Deferred income tax assets, net			81,303
Assets of discontinued operations, non-current			235
Lease liability - operating, current			18,656
Other accrued expenses, current	[1]		13,718
Liabilities of discontinued operations, current			593
Lease liability - operating, non-current			48,238
Other liabilities, non-current	[1]		12,395
Accumulated deficit	[2]		(51,911)
ASC 842 [Member] | Impact of Modified Retrospective Adoption of ASC 842 [Member]
Leases [Line Items]
Prepaid expenses	[1]		(1,502)
Right of use asset			45,963
Deferred income tax assets, net			(325)
Assets of discontinued operations, non-current			57
Lease liability - operating, current			18,656
Other accrued expenses, current	[1]		(5,950)
Liabilities of discontinued operations, current			57
Lease liability - operating, non-current			48,238
Deferred rent obligations	[1]		(12,745)
Other liabilities, non-current	[1]		(5,098)
Accumulated deficit	[2]		$ 1,035

[1] Balances as of December 31, 2018 that related to prepaid rent, remaining lease obligations for vacated spaces and deferred rent obligations were offset with the ROU asset as of January 1, 2019.

[2] Certain leases resulted in a negative ROU asset upon transition to ASC 842 related to vacated spaces that had liabilities previously established. Those leases that resulted in a negative ROU asset were recorded as an adjustment, net of tax, to accumulated deficit within stockholders equity on our condensed consolidated balance sheet as of January 1, 2019