CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Common Stock [Member] Restricted Stock [Member]	Common Stock [Member] Restricted Stock Units (RSUs) [Member]	Common Stock [Member]	Retained Earnings / (Accumulated deficit) [Member] Restricted Stock [Member]	Retained Earnings / (Accumulated deficit) [Member] Restricted Stock Units (RSUs) [Member]	Retained Earnings / (Accumulated deficit) [Member]	Accumulated Other Comprehensive Loss [Member] Restricted Stock [Member]	Accumulated Other Comprehensive Loss [Member] Restricted Stock Units (RSUs) [Member]	Accumulated Other Comprehensive Loss [Member]	Restricted Stock [Member]	Restricted Stock Units (RSUs) [Member]	Total
Balance, beginning at Dec. 31, 2018			$ 1,309,269			$ (269,485)			$ (29,929)			$ 1,009,855
Net income/(loss)			0			(5,626)			0			(5,626)
Other comprehensive loss			0			0			(10,353)			(10,353)
Forfeitures of vested restricted stock awards			(359)			0			0			(359)
Compensation relating to restricted stock units or restricted stock awards	$ 434			$ 0			$ 0			$ 434
Compensation relating to stock option awards		$ 883	504		$ 0	0		$ 0	0		$ 883	504
Balance, ending at Jun. 30, 2019			1,310,731			(275,111)			(40,282)			995,338
Balance, beginning at Mar. 31, 2019			1,309,881			(258,588)			(33,306)			1,017,987
Net income/(loss)			0			(16,523)			0			(16,523)
Other comprehensive loss			0			0			(6,976)			(6,976)
Forfeitures of vested restricted stock awards			(210)			0			0			(210)
Compensation relating to restricted stock units or restricted stock awards	202	587		0	0		0	0		202	587
Compensation relating to stock option awards			271			0			0			271
Balance, ending at Jun. 30, 2019			1,310,731			(275,111)			(40,282)			995,338
Balance, beginning at Dec. 31, 2019			1,313,178			(270,315)			(20,570)			1,022,293
Net income/(loss)			0			97,377			0			97,377
Other comprehensive loss			0			0			(15,511)			(15,511)
Dividends declared and paid			(3,412)			0			0			(3,412)
Forfeitures of vested restricted stock awards			(1,200)			0			0			(1,200)
Compensation relating to restricted stock units or restricted stock awards			508			0			0			508
Compensation relating to stock option awards	406	1,589		0	0		0	0		406	1,589
Repurchase of common stock			(29,997)			0			0			(29,997)
Balance, ending at Jun. 30, 2020			1,281,072			(172,938)			(36,081)			1,072,053
Balance, beginning at Mar. 31, 2020			1,301,938			(237,296)			(34,962)			1,029,680
Net income/(loss)			0			64,358			0			64,358
Other comprehensive loss			0			0			(1,119)			(1,119)
Dividends declared and paid			(1,683)			0			0			(1,683)
Forfeitures of vested restricted stock awards			(495)			0			0			(495)
Compensation relating to restricted stock units or restricted stock awards	$ 177	$ 834		$ 0	$ 0		$ 0	$ 0		$ 177	$ 834
Compensation relating to stock option awards			286			0			0			286
Repurchase of common stock			(19,985)			0			0			(19,985)
Balance, ending at Jun. 30, 2020			$ 1,281,072			$ (172,938)			$ (36,081)			$ 1,072,053