Subsequent Events Subsequent Events (Details Textual) - USD ($)		3 Months Ended								12 Months Ended
	Feb. 17, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 12, 2020
Subsequent Event [Line Items]
Stock Repurchase Program, Authorized Amount													$ 200,000,000
Dividends declared per share (usd per share)		$ 0.25	$ 0.25	$ 0.25	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 0.60	$ 2.30	$ 2.40	$ 1.35
Dividend Declared [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends declared per share (usd per share)	$ 0.25