Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 29, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 28, 2014
Earnings Per Share [Abstract]
Income (loss) from continuing operations, as reported	$ 70,727	$ 153,839	$ (152,628)	$ 15,102	$ (388,578)	$ 33,836	$ 2,796	$ 36,609	$ 87,040	$ (315,337)	$ 476,619
Less: Dividends distributed to Warrants									161	325	0
Less: Undistributed earnings allocated to Warrants									0	0	16,063
Income (loss) from continuing operations attributable to common shareholders for basic EPS									86,879	(315,662)	460,556
Add: Undistributed earnings allocated to dilutive securities									0	0	38
Income (loss) from continuing operations attributable to common shareholders for diluted EPS									86,879	(315,662)	460,594
(Loss) income from discontinued operations, as reported	$ 51,776	$ 8,074	$ 8,935	$ 4,009	$ (7,650)	$ 5,978	$ 6,061	$ 192	72,794	4,581	(44)
Less: Undistributed earnings allocated to Warrants									0	0	1
(Loss) income from discontinued operations attributable to common shareholders for basic and diluted EPS									(72,794)	(4,581)	43
Net income (loss) attributable to common shareholders for basic EPS									14,085	(320,243)	460,599
Net income (loss) attributable to common shareholders for diluted EPS									$ 14,085	$ (320,243)	$ 460,637
Weighted average shares outstanding - basic									90,244	94,686	96,689
Impact of dilutive securities									392	0	234
Weighted average shares outstanding - diluted									90,636	94,686	96,923
Continuing Operations	$ 0.81	$ 1.71	$ (1.66)	$ 0.16	$ (4.15)	$ 0.35	$ 0.03	$ 0.37	$ 0.96	$ (3.33)	$ 4.76
Discontinued Operations	(0.59)	(0.09)	(0.10)	(0.04)	0.08	(0.06)	(0.07)	0.00	(0.80)	(0.05)	0.00
Net Earnings (Loss) Per Common Share	0.22	1.62	(1.76)	0.12	(4.07)	0.29	(0.04)	0.37	0.16	(3.38)	4.76
Continuing Operations	0.81	1.70	(1.66)	0.16	(4.15)	0.35	0.03	0.37	0.96	(3.33)	4.75
Discontinued Operations	(0.59)	(0.09)	(0.10)	(0.04)	0.08	(0.06)	(0.07)	0.00	(0.80)	(0.05)	0.00
Net Earnings (Loss) Per Common Share	$ 0.22	$ 1.61	$ (1.76)	$ 0.12	$ (4.07)	$ 0.29	$ (0.04)	$ 0.37	$ 0.16	$ (3.38)	$ 4.75