Shareholders' Equity Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Feb. 24, 2021
Class of Stock [Line Items]
Proceeds from Issuance of Common Stock	$ 87,329	$ 19
At The Market Equity Program
Class of Stock [Line Items]
Aggregate offering price of common share			$ 500,000
Stock Issued During Period, Shares, New Issues	847,471
Weighted Average Price Per Common Share	$ 104.19
Proceeds from Issuance of Common Stock	$ 87,200
Remaining capacity to issue	404,400
At The Market Equity Program | Commissions
Class of Stock [Line Items]
Payments of Stock Issuance Costs	900
At The Market Equity Program | Other Offering Costs
Class of Stock [Line Items]
Payments of Stock Issuance Costs	$ 200
Forward Sales Contracts
Class of Stock [Line Items]
Weighted Average Price Per Common Share	$ 106.43
Forward Contract Indexed to Issuer's Equity, Indexed Shares	331,318
Forward Sales Contracts | Other Offering Costs
Class of Stock [Line Items]
Payments of Stock Issuance Costs	$ 400