Stockholders' equity and dividend payment (Tables)

12 Months Ended

Dec. 31, 2018

Stockholders' equity:

(Dollars in thousands, except per share data)	Common stock			Preferred stock
Issued at December 31, 2016		93,433,804
Restricted stock issued		1,259,208
New shares issued *		47,724,395
Issued at December 31, 2017		142,417,407
Restricted stock issued		1,175,136
Retirement of treasury shares		(892,497	)
Issued at December 31, 2018		142,700,046
Par value	$	0.01		$	0.01
Shares to be issued assuming conversion of convertible notes due 2019**		6,562,001
Shares to be issued assuming conversion of convertible notes due 2021**		29,761,913
Number of shares authorized for issue at December 31, 2018		250,000,000

Dividend payment:

Dividend payment as of December 31, 2018:		Per share
Payment date:	Total payment	Common
February 28, 2018	$ 2.9 million	$	0.02
May 30, 2018	$ 2.9 million	$	0.02
August 31, 2018	$ 2.9 million	$	0.02
November 23, 2018	$ 2.9 million	$	0.02
Total payment as of December 31, 2018:	$ 11.5 million	$	0.08

Dividend payment as of December 31, 2017:
Payment date:
February 22, 2017	$ 7.6 million	$	0.08
May 31, 2017	$ 10.1 million	$	0.08
August 31, 2017	$ 2.8 million	$	0.02
December 6, 2017	$ 2.8 million	$	0.02
Total payment as of December 31, 2017:	$ 23.3 million	$	0.20

Dividend payment as of December 31, 2016:
Payment date:
February 24, 2016	$ 19.7 million	$	0.21
May 25, 2016	$ 23.3 million	$	0.25
August 31, 2016	$ 21.5 million	$	0.23
November 23, 2016	$ 1.9 million	$	0.02
Total payment as of December 31, 2016:	$ 66.4 million	$	0.71