Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2013	$ 1,335,869	$ 1,091	$ 802,124	$ 1,880,320	$ (1,347,677)	$ 11
Balance, shares at Dec. 31, 2013		109,108
Net (loss) earnings	96,422			96,422
Total other comprehensive loss	(4,656)					(4,656)
Exercise of stock options, shares		212
Exercise of stock options	4,647	$ 2	4,645
Vesting of restricted share units, shares		33
Vesting of restricted share units	1	$ 1
Tax effects of stock awards vested and options exercised	(150)		(150)
Stock-based compensation	6,559		6,559
Dividends declared	(49,297)			(49,297)
Balance at Dec. 31, 2014	1,389,395	$ 1,094	813,178	1,927,445	(1,347,677)	(4,645)
Balance, shares at Dec. 31, 2014		109,353
Net (loss) earnings	(953,520)			(953,520)
Total other comprehensive loss	(6,399)					(6,399)
Exercise of stock options, shares		66
Exercise of stock options	1,485	$ 0	1,485
Vesting of restricted share units, shares		23
Vesting of restricted share units	0	$ 0
Tax effects of stock awards vested and options exercised	(5,865)		(5,865)
Stock-based compensation	9,541		9,541
Dividends declared	(51,047)			(51,047)
Balance at Dec. 31, 2015	383,590	$ 1,094	818,339	922,878	(1,347,677)	(11,044)
Balance, shares at Dec. 31, 2015		109,442
Net (loss) earnings	(105,195)			(105,195)
Total other comprehensive loss	(5,188)
Vesting of restricted share units, shares		77
Vesting of restricted share units	0	$ 1	(1)
Tax effects of stock awards vested and options exercised	(440)		(440)
Stock-based compensation	9,209		9,209
Dividends declared	(17,043)			(17,043)
Balance at Dec. 31, 2016	$ 264,933	$ 1,095	$ 827,107	$ 800,640	$ (1,347,677)	$ (16,232)
Balance, shares at Dec. 31, 2016		109,519