Shareholders' Equity (Narrative) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 $ / shares shares
Class of Stock [Line Items]
Stock repurchase program, authorized amount | $	$ 200,000
Common stock, shares issued | shares	93,686,311	93,686,311
Stock repurchase program, remaining authorized repurchase amount | $	$ 6,000
Common stock par value (in usd per share)	$ 0.01	$ 0.01
Depositary shares, ownership of preferred shares	0.001
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Preferred stock, liquidation preference per share (in usd per share)	$ 25,000
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares issued | shares	93,686,311
Treasury stock acquired, average cost per share (in usd per share)	$ 36.38
Stock repurchase program, remaining authorized repurchase amount | $	$ 123,400
Series F Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)	5.25%
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 25