Commitments and Contingencies - Summary of Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
INTI Education Holdings Sdn Bhd
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling interest, noncontrolling owners, ownership percent	10.10%
Puttable common stock \| INTI Education Holdings Sdn Bhd
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of June 30, 2019 redeemable within 12-months:	$ 10,779
Reported Value	10,779
Puttable non-controlling interest
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of June 30, 2019 redeemable within 12-months:	10,779
Reported Value	10,779
Puttable common stock - not currently redeemable
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of June 30, 2019 redeemable within 12-months:	0
Reported Value	1,714
Total redeemable noncontrolling interests and equity
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of June 30, 2019 redeemable within 12-months:	10,779
Reported Value	$ 12,493	$ 14,396

As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (16)(c)
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 15
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph (12)(c)
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section S99
-Paragraph 3A
-Subparagraph 14
-URI http://asc.fasb.org/extlink&oid=65877616&loc=SL6540498-122764

Name:	us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant