Basic and diluted loss per common share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income (loss) before extraordinary net gain	$ 5,951	$ (80,115)	$ (13,655)
Extraordinary gain on extinguishment of junior subordinated debentures, net of income taxes	0	32,839	0
Net income (loss)	5,951	(47,276)	(13,655)
Weighted-average shares outstanding - basic (in shares)	47,127,737	43,628,044	2,804,831
Dilutive securities	$ 150,287	$ 0	$ 0
Weighted-average shares outstanding - diluted (in shares)	47,278,024	43,628,044	2,804,831
Common stock equivalent shares excluded due to antidilutive effect	139,346	114,593	48,141
Basic and diluted net income (loss) per common share:
Income (loss) before extraordinary net gain (in dollars per share)	$ 0.13	$ (1.83)	$ (4.87)
Extraordinary net gain (in dollars per share)	$ 0	$ 0.75	$ 0
Net income (loss) (in dollars per share)	$ 0.13	$ (1.08)	$ (4.87)