CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Common Shares [Member]	Additional Paid-in Capital [Member]	Net Income [Member]	Cash Dividends [Member]	Accumulated Deficit [Member]	Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2008	$ 470,313	$ 614,241,646			$ (107,786,658)	$ (35,498,525)	$ 471,426,776
Balance (in shares) at Dec. 31, 2008	47,031,300
Comprehensive income :
Net income (loss)	0	0	33,287,271	0	33,287,271	0	33,287,271
Net unrealized gain on derivatives	0	0	0	0	0	4,855,592	4,855,592
Comprehensive income	0	0	0	0		0	38,142,863
Net income (loss)	0	0	33,287,271	0	33,287,271	0	33,287,271
Vesting of restricted shares, net of shares withheld for employee tax	2,479	(1,112,066)	0	0	0	0	(1,109,587)
Vesting of restricted shares, net of shares withheld for employee tax (in shares)	247,872
Issuance of common shares, net of issuance costs	148,475	97,142,571	0	0	0	0	97,291,046
Issuance of common shares, net of issuance costs (in shares)	14,847,493
Non-cash compensation	0	13,977,974	0	0	0	0	13,977,974
Balance at Dec. 31, 2009	621,267	724,250,125			(74,499,387)	(30,642,933)	619,729,072
Balance (in shares) at Dec. 31, 2009	62,126,665
Comprehensive income :
Net income (loss)	0	0	26,844,650	0	26,844,650	0	26,844,650
Net unrealized gain on derivatives	0	0	0	0	0	8,507,426	8,507,426
Comprehensive income	0	0	0	0		0	35,352,076
Net income (loss)	0	0	26,844,650	0	26,844,650	0	26,844,650
Vesting of restricted shares, net of shares withheld for employee tax	4,337	(740,780)	0	0	0	0	(736,443)
Vesting of restricted shares, net of shares withheld for employee tax (in shares)	433,771
Non-cash compensation	0	14,741,813	0	0	0	0	14,741,813
Balance at Dec. 31, 2010	625,604	738,251,158			(47,654,737)	(22,135,507)	669,086,518
Balance (in shares) at Dec. 31, 2010	62,560,436
Comprehensive income :
Net income (loss)	0	0	(14,819,749)	0	(14,819,749)	0	(14,819,749)
Change in unrealized gain on investments	0	0	0	0	0	33,103	33,103
Net unrealized gain on derivatives	0	0	0	0	0	12,649,391	12,649,391
Comprehensive income	0	0	0	0	0	0	(2,137,255)
Net income (loss)	0	0	(14,819,749)	0	(14,819,749)	0	(14,819,749)
Vesting of restricted shares, net of shares withheld for employee tax	4,429	(1,685,078)	0	0	0	0	(1,680,649)
Vesting of restricted shares, net of shares withheld for employee tax (in shares)	442,850
Non-cash compensation	0	8,907,089	0	0	0	0	8,907,089
Balance at Dec. 31, 2011	$ 630,033	$ 745,473,169			$ (62,474,486)	$ (9,453,013)	$ 674,175,703
Balance (in shares) at Dec. 31, 2011	63,003,286