Debt Debt - Cash Pool (Details) $ in Thousands	Jun. 30, 2020 USD ($) cash_pool	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Number of cash pools | cash_pool	2
QRS Cash Pool
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
Gross Cash Position	$ 350,500	$ 372,100
Outstanding Debit Balances	(347,300)	(369,000)
Net Cash Position	$ 3,200	3,100
TRS Cash Pool
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
Gross Cash Position	$ 355,900	319,800
Outstanding Debit Balances	(355,000)	(301,300)
Net Cash Position	$ 900	$ 18,500