Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Voting Common Stock [Member] Common Stock [Member]	Nonvoting Common Stock [Member] Common Stock [Member]	Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Shareholders' Equity [Member]	Total
Balance at Dec. 31, 2014	$ 216	$ 95	$ 1,017,520	$ (9,592)	$ (803,378)	$ (29,221)	$ 175,640
Balance, shares at Dec. 31, 2014	21,569	9,506		154
Net income (loss)					(70,282)
Other comprehensive income (loss)						523
Comprehensive income (loss)							(69,759)
Settlement of restricted stock units
Settlement of restricted stock units, shares	13
Tax benefit associated with stock-based compensation			2,609				2,609
Balance at Dec. 31, 2015	$ 216	$ 95	1,020,129	$ (9,592)	(873,660)	(28,698)	108,490
Balance, shares at Dec. 31, 2015	21,582	9,506		154
Net income (loss)					63,238			$ 63,238
Other comprehensive income (loss)						9,576		9,576
Comprehensive income (loss)							72,814	$ 72,814
Balance at Jun. 30, 2016	$ 216	$ 95	$ 1,020,129	$ (9,592)	$ (810,422)	$ (19,122)	$ 181,304
Balance, shares at Jun. 30, 2016	21,582	9,506		154