Stock Compensation Plans (Weighted-average remaining contractual lives of stock options outstanding) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding - number outstanding | shares	1,168
Weighted average remaining contractual term	1 year 11 months
Options outstanding - weighted average per share exercise price	$ 11
Options exercisable - number exercisable | shares	1,168
Options exercisable - weighted average per share exercise price	$ 11
$0.01 to $10.00 [Member]
Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding - number outstanding | shares	264
Weighted average remaining contractual term	2 years 10 months
Options outstanding - weighted average per share exercise price	$ 8
Options exercisable - number exercisable | shares	264
Options exercisable - weighted average per share exercise price	$ 8
Exercise price range, lower range limit	0.01
Exercise price range, upper range limit	$ 10.00
$10.01 to $20.00 [Member]
Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding - number outstanding | shares	904
Weighted average remaining contractual term	1 year 7 months
Options outstanding - weighted average per share exercise price	$ 12
Options exercisable - number exercisable | shares	904
Options exercisable - weighted average per share exercise price	$ 12
Exercise price range, lower range limit	10.01
Exercise price range, upper range limit	20.00
$20.01 to $30.00 [Member]
Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	20.01
Exercise price range, upper range limit	30.00
$30.01 to $40.00 [Member]
Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	30.01
Exercise price range, upper range limit	40.00
$40.01 to $45.00 [Member]
Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	40.01
Exercise price range, upper range limit	$ 45.00