Commitments and Contingencies - Summary of Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
INTI Education Holdings Sdn Bhd
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling interest, noncontrolling owners, ownership percent	10.10%
Pearl Retail Solutions Private Limited
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling interest, noncontrolling owners, ownership percent	10.00%
Puttable common stock | INTI Education Holdings Sdn Bhd
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of March 31, 2019 redeemable within 12-months:	$ 10,109
Reported Value	10,109
Puttable common stock | Pearl Retail Solutions Private Limited
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of March 31, 2019 redeemable within 12-months:	2,086
Reported Value	2,086
Puttable non-controlling interest
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of March 31, 2019 redeemable within 12-months:	12,195
Reported Value	12,195
Puttable common stock - not currently redeemable
Redeemable Noncontrolling Interest [Line Items]
Estimated Value as of March 31, 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 March 31, 2019 redeemable within 12-months:	12,195
Reported Value	$ 13,909	$ 14,396