Fair value measurements (Tables)

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Financial instruments measured at fair value on recurring basis

At December 31, 2020, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1	Level 2	Level 3	Fair value measurements
	(in $ thousands)
Investments in securities:
Debt securities:
Municipal	—	47,603	—	47,603
Corporate	—	305,450	—	305,450
Foreign	—	271,711	—	271,711
U.S. Treasury Bonds	—	6,622	—	6,622
Equity securities:	53,001	—	—	53,001
	53,001	631,386	—	684,387

At December 31, 2019, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1	Level 2	Level 3	Fair value measurements
	(in $ thousands)
Investments in securities:
Debt securities:
Municipal	—	53,823	—	53,823
Corporate	—	309,142	—	309,142
Foreign	—	236,073	—	236,073
U.S. Treasury Bonds	—	6,683	—	6,683
Equity securities:	39,318	—	—	39,318
	39,318	605,721	—	645,039