Stock Plans (Restricted Shares Outstanding) (Details) - Restricted Stock [Member] $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of period (in shares) | shares	900,000
Restricted stock vested (in shares) | shares	(387,000)
Restricted stock forfeited (in shares) | shares	(14,000)
Balance at end of period (in shares) | shares	499,000
Balance at beginning of period (in dollars per shares) | $ / shares	$ 10.57
Restricted stock vested (in dollars per shares) | $ / shares	15.04
Restricted stock forfeited (in dollars per shares) | $ / shares	11.57
Balance at end of period (in dollars per shares) | $ / shares	$ 7.07
Balance at beginning of period, Aggregate fair value | $	$ 1