Goodwill and Intangible Assets - Finite-lived Intangible Assets Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Finite-lived Intangible Assets, Gross [Roll Forward]
Intangible assets, January 1			$ 35,240	$ 35,240	$ 35,240
Additions			0
Total intangible assets, end of year	$ 35,240		35,240		35,240
Accumulated Amortization [Roll Forward]
Accumulated amortization, January 1			(29,985)	(27,345)	(27,345)
Current year amortization	(517)	$ (658)	(1,033)	$ (1,318)	(2,640)
Total accumulated amortization	(31,018)		(31,018)		(29,985)
Net intangible assets
Net intangible assets, end of year	4,222		4,222		5,255
Infinite-lived intangible assets	6,892		6,892		6,892
Total net intangible assets	$ 11,114		$ 11,114		$ 12,147