Consolidated Statements of Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Balance at the beginning at Dec. 31, 2018	$ 416	$ 1,740,163	$ (687,272)	$ 1,053,307
Increase (Decrease) in Shareholders' Equity
Net loss			(7,801)	(7,801)
Nonvested stock amortization		452		452
Balance at the end at Mar. 31, 2019	416	1,740,615	(695,073)	1,045,958
Increase (Decrease) in Shareholders' Equity
Net loss			(34,476)	(34,476)
Nonvested stock amortization		569		569
Balance at the end at Jun. 30, 2019	416	1,741,184	(729,549)	1,012,051
Balance at the beginning at Dec. 31, 2019	417	1,721,268	(743,257)	978,428
Increase (Decrease) in Shareholders' Equity
Net loss			(120,350)	(120,350)
Issuance of vested RSUs, net of forfeitures	1	(1)
Cash dividends declared		(7,363)		(7,363)
Nonvested stock amortization		481		481
Balance at the end at Mar. 31, 2020	418	1,714,385	(863,607)	851,196
Increase (Decrease) in Shareholders' Equity
Net loss			(18,204)	(18,204)
Cash dividends declared		(842)		(842)
Nonvested stock amortization		476		476
Balance at the end at Jun. 30, 2020	$ 418	$ 1,714,019	$ (881,811)	$ 832,626