Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (shares) at Dec. 31, 2015			72,851	20,250
Stockholders' equity - beginning balance at Dec. 31, 2015		$ 245,972	$ 94	$ (283,913)	$ 353,241	$ 227,463	$ (50,913)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation		10,736			10,736
Exercises of stock options and issuance of restricted stock awards (shares)			749	37
Exercises of stock options and issuance of restricted stock awards		96	$ 0	$ (324)	420
Series A preferred dividends		(12,000)				(12,000)
Series A preferred accretion		(3,244)				(3,244)
Net income (loss)		(16,494)				(16,494)
Other comprehensive income (loss)		(4,683)					(4,683)
Ending balance (shares) at Dec. 31, 2016			73,600	20,287
Stockholders' equity - ending balance at Dec. 31, 2016		220,383	$ 94	$ (284,237)	364,397	195,725	(55,596)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation		11,619			11,619
Exercises of stock options and issuance of restricted stock awards (shares)			850	41
Exercises of stock options and issuance of restricted stock awards		(3,045)	$ 1	$ (75)	(2,971)
Repurchases of common stock (shares)			5,659	5,659
Repurchases of common stock		(50,000)		$ (50,000)
Series A preferred dividends		(12,000)				(12,000)
Series A preferred accretion		(3,532)				(3,532)
Net income (loss)		10,238				10,238
Other comprehensive income (loss)		12,202					12,202
Ending balance (shares) at Dec. 31, 2017			68,791	25,987
Stockholders' equity - ending balance at Dec. 31, 2017		185,865	$ 95	$ (334,312)	373,045	190,431	(43,394)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation		13,732			13,732
Exercises of stock options and issuance of restricted stock awards (shares)			1,238	49
Exercises of stock options and issuance of restricted stock awards		(772)	$ 1	$ (48)	(725)
Repurchases of common stock (shares)			3,620	3,620
Repurchases of common stock		(63,131)		$ (63,131)
Series A preferred repurchase	[1]	(84,224)				(84,224)
Series A preferred conversion (shares)	[2]		6,897
Series A preferred conversion	[2]	100,000	$ 7		99,993
Series A preferred dividends	[3]	(24,000)				(24,000)
Series A preferred accretion	[4]	(17,567)			(6,138)	(11,429)
Net income (loss)		50,437
Other comprehensive income (loss)		(11,258)					(11,258)
Other		1,226			1,226
Ending balance (shares) at Dec. 31, 2018			73,306	29,656
Stockholders' equity - ending balance at Dec. 31, 2018		$ 150,308	$ 103	$ (397,491)	$ 481,133	$ 121,215	$ (54,652)

[1] Repurchase premium is the difference between cash paid and the carrying value of 100,000 shares of Series A Convertible Preferred Stock repurchased, including other costs associated with the transaction.

[2] Represents the issuance of common stock upon conversion of 100,000 shares of Series A Convertible Preferred Stock.

[3] Represents Series A Convertible Preferred Stock cash dividends declared and paid of $9.0 million, and $15.0 million of payments paid and payable to induce conversion.

[4] Represents total accretion of $17.6 million, net of $6.1 million acquired value of beneficial conversion feature attributable to repurchased Series A Convertible Preferred Stock.