Commitments and Contingencies - Summary of Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
INTI Education Holdings Sdn Bhd
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling interest, noncontrolling owners, ownership percent allowed to be sold		10.10%
Pearl Retail Solutions Private Limited
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling interest, noncontrolling owners, ownership percent allowed to be sold		10.00%
Puttable Common Stock
Redeemable Noncontrolling Interest [Line Items]
Reported Value	$ 10,609
Puttable Common Stock | INTI Education Holdings Sdn Bhd
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of December 31, 2018 redeemable within 12-months:	$ 10,609
Noncontrolling interest, noncontrolling owners, ownership percent allowed to be sold	10.10%
Puttable Common Stock | Pearl Retail Solutions Private Limited
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of December 31, 2018 redeemable within 12-months:	$ 2,012
Reported Value	2,012
Puttable Preferred Stock | Stamford International University
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of December 31, 2018 redeemable within 12-months:	62
Reported Value	62
Puttable Non-controlling Interest
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of December 31, 2018 redeemable within 12-months:	12,683
Reported Value	12,683
Puttable common stock - not currently redeemable
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of December 31, 2018 redeemable within 12-months:	0
Reported Value	1,713	$ 2,286
Puttable Arrangements - Common and Preferred Stock
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of December 31, 2018 redeemable within 12-months:	12,683
Reported Value	$ 14,396	$ 13,721