Earnings per Share (EPS) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Income (loss) from continuing operations		$ 10,773	$ 5,345	$ (208,071)	$ 32,112
Numerator:
Income (loss) from discontinued operations, net of tax		616	(8,470)	7,648	(14,199)
Net income (loss)		11,389	(3,125)	(200,423)	17,913
Less: Preference stock dividend		0	0	0	8
Income (loss) attributable to common stockholders (numerator for basic EPS)		$ 11,389	$ (3,125)	$ (200,423)	$ 17,905
Denominator:
Weighted-average shares used in basic EPS (in shares)		171,828,000	170,326,000	171,388,000	178,048,000
Dilutive effect of common stock equivalents (in shares)		2,876,000	875,000	0	1,048,000
Weighted-average shares used in diluted EPS (in shares)		174,704,000	171,201,000	171,388,000	179,096,000
Basic earnings (loss) per share:
Continuing operations (in dollars per share)	[1]	$ 0.06	$ 0.03	$ (1.21)	$ 0.18
Discontinued operations (in dollars per share)	[1]	0	(0.05)	0.04	(0.08)
Net (loss) income (in dollars per share)	[1]	0.07	(0.02)	(1.17)	0.10
Diluted earnings (loss) per share:
Continuing operations (in dollars per share)	[1]	0.06	0.03	(1.21)	0.18
Discontinued operations (in dollars per share)	[1]	0	(0.05)	0.04	(0.08)
Net (loss) income (in dollars per share)	[1]	$ 0.07	$ (0.02)	$ (1.17)	$ 0.10
Common stock equivalents excluded from calculation of diluted earnings per share because their impact would be anti-dilutive (in shares)		14,828,000	16,182,000	15,855,000	16,166,000
Dilutive effect of common stock equivalents				1,604,000

[1] The sum of the earnings per share amounts may not equal the totals due to rounding.