Senior Notes - Carrying Amount of Senior Notes (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total Senior Notes debt	$ 1,037,062	$ 989,422
$250 million 5.625% Senior Notes due February 2020, net
Debt Instrument [Line Items]
Total Senior Notes debt	0	249,909
$250 million 5.500% Senior Notes due January 2024, net
Debt Instrument [Line Items]
Total Senior Notes debt	249,117	249,005
3.850% Senior Notes due January 2030, net
Debt Instrument [Line Items]
Total Senior Notes debt	297,342	0
$500 million 6.000% Senior Notes due January 2043, net
Debt Instrument [Line Items]
Total Senior Notes debt	$ 490,603	$ 490,508