Stock Plans (Restricted Shares Outstanding) (Details) - Restricted Stock [Member] $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of period (in shares) | shares	1,858,000
Restricted stock granted (in shares) | shares	105,000
Restricted stock vested (in shares) | shares	(711,000)
Restricted stock forfeited (in shares) | shares	(19,000)
Balance at end of period (in shares) | shares	1,233,000
Balance at beginning of period (in dollars per shares) | $ / shares	$ 16.02
Restricted stock granted (in dollars per shares) | $ / shares	2.00
Restricted stock vested (in dollars per shares) | $ / shares	21.78
Restricted stock forfeited (in dollars per shares) | $ / shares	32.44
Balance at end of period (in dollars per shares) | $ / shares	$ 11.26
Balance at beginning of period, Aggregate fair value | $	$ 4
Restricted stock vested, Aggregate fair value | $	(1)
Balance at end of period, Aggregate fair value | $	$ 1