Derivative Instruments (Details) $ in Thousands		9 Months Ended		24 Months Ended
	May 27, 2020 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2011 USD ($) instrument	Dec. 31, 2019
Derivative [Line Items]
Amortization of interest expense		$ 1,351	$ 1,013
Senior Notes | 4.20% Senior Notes, due December 2021
Derivative [Line Items]
Interest rate on senior notes		4.20%			4.20%
Pre-tax amount included in Accumulated other comprehensive income (loss)		$ 3,400
Senior Notes | 4.50% Senior Notes, due December 2020
Derivative [Line Items]
Interest rate on senior notes		4.50%			4.50%
Amount to be recognized from hedged transactions within 12 months, approximate	$ 1,400
Interest Rate Contract
Derivative [Line Items]
Number of instruments held | instrument				2
Interest Rate Exchange Agreement Expiring 2010 and 2011
Derivative [Line Items]
Amortization of interest expense				$ 68,900
Term of amortized interest expense, years				10 years