Other Non-Current Liabilities - Summary of Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Liabilities, Noncurrent [Abstract]
Derivative instruments	$ 3,496	$ 1,250
Unrecognized tax benefits	1,047	1,047
Retirement benefits	6,803	6,517
Deferred transition revenue	1,586	1,911
Accrued capital expenditure	3,373	0
Others	2,904	987
Finance lease liabilities	357	430
Other non-current liabilities	$ 19,566	$ 12,142
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent