Fair Value Measurements - Schedule of Certain Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value Measurements
Carrying amount	$ 1,172,399	$ 610,397
Recurring basis
Fair Value Measurements
Fair Value	1,022,314	605,286
Recurring basis | Level 1
Fair Value Measurements
Fair Value	0	0
Recurring basis | Level 2
Fair Value Measurements
Fair Value	0	0
Recurring basis | Level 3
Fair Value Measurements
Fair Value	$ 1,022,314	$ 605,286