Shareholders' Equity (Preferred Stock) (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) $ / shares	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) item $ / shares	Jun. 30, 2019 USD ($)
Shareholders' Equity [Abstract]
Redeemable preferred stock, redemption price per share | $ / shares	$ 25.00		$ 25.00
Distributions to preferred shareholders | $	$ 12,000,000.0	$ 13,000,000.0	$ 24,093,000	$ 25,918,000
Number of quarterly dividends in arrearage before preferred shareholders can elect additional board members | item			6
Number of additional board members the preferred shareholders can elect in the case of an excess arrearage of quarterly dividends | item			2
Dividends in arrears | $			$ 0