Fair value of financial instruments - Schedule of Financial Liabilities Not Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Carrying Value
Financial liabilities not recorded at fair value
Total liabilities	$ 1,162,792	$ 1,248,973
Carrying Value | Revolving Credit Facility
Financial liabilities not recorded at fair value
Total liabilities		84,667
Carrying Value | Property Loan
Financial liabilities not recorded at fair value
Total liabilities	102,073	101,631
Fair Value | Level 1
Financial liabilities not recorded at fair value
Total liabilities	0	0
Fair Value | Level 1 | Revolving Credit Facility
Financial liabilities not recorded at fair value
Total liabilities		0
Fair Value | Level 1 | Property Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Fair Value | Level 2
Financial liabilities not recorded at fair value
Total liabilities	0	0
Fair Value | Level 2 | Revolving Credit Facility
Financial liabilities not recorded at fair value
Total liabilities		0
Fair Value | Level 2 | Property Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Fair Value | Level 3
Financial liabilities not recorded at fair value
Total liabilities	1,159,419	1,225,810
Fair Value | Level 3 | Revolving Credit Facility
Financial liabilities not recorded at fair value
Total liabilities		84,769
Fair Value | Level 3 | Property Loan
Financial liabilities not recorded at fair value
Total liabilities	111,985	109,871
Term Loan | Carrying Value | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	969,728	971,920
Term Loan | Fair Value | Level 1 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term Loan | Fair Value | Level 2 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term Loan | Fair Value | Level 3 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	952,973	936,799
Term A1 Loan | Carrying Value | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	33,879	33,792
Term A1 Loan | Fair Value | Level 1 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term A1 Loan | Fair Value | Level 2 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term A1 Loan | Fair Value | Level 3 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	35,433	35,182
Term A2 Loan | Carrying Value | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	30,008	29,930
Term A2 Loan | Fair Value | Level 1 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term A2 Loan | Fair Value | Level 2 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term A2 Loan | Fair Value | Level 3 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	31,383	31,161
Term A3 Loan | Carrying Value | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	27,104	27,033
Term A3 Loan | Fair Value | Level 1 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term A3 Loan | Fair Value | Level 2 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	0	0
Term A3 Loan | Fair Value | Level 3 | Term Loan
Financial liabilities not recorded at fair value
Total liabilities	$ 27,645	$ 28,028