NET INCOME PER SHARE - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Basic net income per share:
Net income from continuing operations	$ 12,755	$ 12,020	$ 26,173	$ 23,752
Net loss from discontinued operations	0	(7,022)	0	(10,370)
Net income	$ 12,755	$ 4,998	$ 26,173	$ 13,382
Weighted average common shares outstanding, basic (in shares)	37,196	33,032	37,037	32,884
Basic net income per common share from continuing operations (in dollars per share)	$ 0.34	$ 0.36	$ 0.71	$ 0.72
Basic net loss per common share from discontinued operations (in dollars per share)	0.00	(0.21)	0.00	(0.32)
Net income per share - basic (in dollars per share)	$ 0.34	$ 0.15	$ 0.71	$ 0.40
Diluted net income per share:
Net income from continuing operations	$ 12,755	$ 12,020	$ 26,173	$ 23,752
Net loss from discontinued operations	0	(7,022)	0	(10,370)
Net income	$ 12,755	$ 4,998	$ 26,173	$ 13,382
Weighted average common shares outstanding, basic (in shares)	37,196	33,032	37,037	32,884
Effect of dilutive securities:
2016 Convertible notes (in shares)	1,598	477	1,125	268
Stock options and restricted stock (in shares)	561	430	609	492
Weighted average common shares for diluted earnings per share (in shares)	39,355	33,939	38,771	33,644
Diluted net income per common share from continuing operations (in dollars per share)	$ 0.32	$ 0.35	$ 0.68	$ 0.71
Diluted net loss per common share from discontinued operations (in dollars per share)	0.00	(0.21)	0.00	(0.31)
Net income per share - diluted (in dollars per share)	$ 0.32	$ 0.14	$ 0.68	$ 0.40