Shareholders' Equity (Shares Issued and Outstanding) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - January 1 (in shares)	43,701,064
Shares outstanding - January 1 (in shares)	43,701,064
Shares issued - December 31 (in shares)	41,187,413	43,701,064
Shares outstanding - December 31 (in shares)	41,187,413	43,701,064
Common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued - January 1 (in shares)	43,701,000	38,442,000	43,646,000
Shares outstanding - January 1 (in shares)	43,701,000	38,442,000	43,646,000
Issuance of shares	0	7,435,000	0
Repurchase of shares (in shares)	(2,741,000)	(2,473,000)	(5,355,000)
Exercise of options and issuance of restricted stock awards	227,000	297,000	151,000
Shares issued - December 31 (in shares)	41,187,000	43,701,000	38,442,000
Shares outstanding - December 31 (in shares)	41,187,000	43,701,000	38,442,000