Earnings (Loss) Per Common Share (Impact Of Company's Stock Price On Assuming Dilution Calculation For The Subordinated Convertible Notes) (Details) - Subordinated Convertible Notes Due 2029	9 Months Ended
	Sep. 29, 2017 $ / shares shares
$36.75
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Share price (in dollars per share) | $ / shares	$ 36.75
Incremental common shares attributable to contingently issuable shares (in shares)	0
$36.75 | Total Treasury Method Incremental Shares
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Incremental common shares attributable to contingently issuable shares (in shares)	0
$38.75
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Share price (in dollars per share) | $ / shares	$ 38.75
Incremental common shares attributable to contingently issuable shares (in shares)	603,152
$38.75 | Total Treasury Method Incremental Shares
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Incremental common shares attributable to contingently issuable shares (in shares)	603,152
$40.75
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Share price (in dollars per share) | $ / shares	$ 40.75
Incremental common shares attributable to contingently issuable shares (in shares)	1,147,099
$40.75 | Total Treasury Method Incremental Shares
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Incremental common shares attributable to contingently issuable shares (in shares)	1,147,099
$42.75
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Share price (in dollars per share) | $ / shares	$ 42.75
Incremental common shares attributable to contingently issuable shares (in shares)	1,640,151
$42.75 | Total Treasury Method Incremental Shares
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Incremental common shares attributable to contingently issuable shares (in shares)	1,640,151
$44.75
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Share price (in dollars per share) | $ / shares	$ 44.75
Incremental common shares attributable to contingently issuable shares (in shares)	2,089,131
$44.75 | Total Treasury Method Incremental Shares
Changes In Company Stock Price Inclusion Of Additional Shares [Line Items]
Incremental common shares attributable to contingently issuable shares (in shares)	2,089,131