Shareholders' Equity (Rollforward of Shares Issued and Outstanding) (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - January 1 (in shares)	42,207,390
Shares outstanding - January 1 (in shares)	42,207,390
Shares issued - December 31 (in shares)	44,148,116	42,207,390
Shares outstanding - December 31 (in shares)	44,148,116	42,207,390
Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - January 1 (in shares)	42,207,000	40,024,000	41,187,000
Shares outstanding - January 1 (in shares)	42,207,000	40,024,000	41,187,000
Issuance of shares (in shares)	1,739,000	1,947,000	0
Repurchase of shares (in shares)	0	0	(1,322,000)
Exercise of options and issuance of restricted stock awards (in shares)	202,000	236,000	159,000
Shares issued - December 31 (in shares)	44,148,000	42,207,000	40,024,000
Shares outstanding - December 31 (in shares)	44,148,000	42,207,000	40,024,000