Schedule I - Condensed Financial Information of Registrant - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 146,919	$ 20,931	$ 116,353
Prepayments and other assets	47,638	44,691
Total assets	2,097,665	2,196,964
LIABILITIES AND SHAREHOLDERS' EQUITY
Trade and other payables	123,410	181,603
Total liabilities	1,529,529	1,387,313
Total shareholders’ equity	568,136	809,651	$ 839,841	$ 599,549
Total liabilities and shareholders' equity	2,097,665	2,196,964
Parent Company
ASSETS
Cash and cash equivalents	10,534	327
Intercompany receivables from subsidiaries	506	125
Prepayments and other assets	140	119
Investment in subsidiaries	708,450	809,338
Total assets	719,630	809,909
LIABILITIES AND SHAREHOLDERS' EQUITY
Trade and other payables	185	258
Advances from subsidiaries	151,309	0
Total liabilities	151,494	258
Total shareholders’ equity	568,136	809,651
Total liabilities and shareholders' equity	$ 719,630	$ 809,909