Equity Incentive Programs (Schedule of Restricted Stock and Restricted Stock Unit Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	$ 15.8
Estimated Future Expense in Year One
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	9.8
Estimated Future Expense in Year Two
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	5.3
Estimated Future Expense in Year Three
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	$ 0.7
Restricted Stock and Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of days dividends will be paid after vesting, maximum	45 days
Weighted- Average Grant Date Fair Value Per Share
Compensation expense recognized	$ 13.8	$ 14.7	$ 15.5
Total future compensation expense	15.8
Restricted Stock and Restricted Stock Units (RSUs) | Estimated Future Expense in Year One
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	9.8
Restricted Stock and Restricted Stock Units (RSUs) | Estimated Future Expense in Year Two
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	5.3
Restricted Stock and Restricted Stock Units (RSUs) | Estimated Future Expense in Year Three
Weighted- Average Grant Date Fair Value Per Share
Total future compensation expense	$ 0.7
Restricted Stock
Shares
Nonvested at beginning of year, (in shares)	2,335,916
Granted, Units (in shares)	1,503,344
Vested (in shares)	(1,118,071)
Forfeited, Units (in shares)	(97,218)
Nonvested at end of year, (in shares)	2,623,971	2,335,916
Weighted- Average Grant Date Fair Value Per Share
Nonvested, beginning of year, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	$ 17.36
Granted, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	12.31
Vested, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	9.46
Forfeited, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	17.72
Nonvested, end of year, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	$ 17.82	$ 17.36
Nonvested, Weighted- Average Remaining Contractual Term (Years)	1 year 6 months	1 year
Restricted Stock Units (RSUs)
Shares
Nonvested at beginning of year, (in shares)	107,092
Granted, Units (in shares)	186,807
Vested (in shares)	(58,187)
Forfeited, Units (in shares)	(5,091)
Nonvested at end of year, (in shares)	230,621	107,092
Weighted- Average Grant Date Fair Value Per Share
Nonvested, beginning of year, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	$ 16.70
Granted, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	12.33
Vested, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	9.51
Forfeited, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	26.88
Nonvested, end of year, Weighted-Average Grant Date Fair Value Per Share (in dollars per share)	$ 14.75	$ 16.70
Nonvested, Weighted- Average Remaining Contractual Term (Years)	1 year 10 months 24 days	9 months 18 days