Earnings per Share (EPS) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
(Loss) income from continuing operations		$ (1,429)	$ 51,483
Numerator:
(Loss) income from discontinued operations, net of tax		(1,230)	8,487
Net (loss) income		(2,659)	59,970
Less: Preference stock dividend		8	8
(Loss) income attributable to common stockholders (numerator for basic EPS)		$ (2,667)	$ 59,962
Denominator:
Weighted-average shares used in basic EPS (in shares)		185,971	186,863
Effect of dilutive shares (in shares)		0	1,312
Weighted-average shares used in diluted EPS (in shares)		185,971	188,175
Basic (loss) earnings per share:
Continuing operations (in dollars per share)	[1]	$ (0.01)	$ 0.28
Discontinued operations (in dollars per share)	[1]	(0.01)	0.05
Net (loss) income (in dollars per share)	[1]	(0.01)	0.32
Diluted (loss) earnings per share:
Continuing operations (in dollars per share)	[1]	(0.01)	0.27
Discontinued operations (in dollars per share)	[1]	(0.01)	0.05
Net (loss) income (in dollars per share)	[1]	$ (0.01)	$ 0.32
Anti-dilutive options excluded from diluted earnings per share (in shares)		14,989	11,636

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