Stockholders' Equity (Details) (USD $)	1 Months Ended	12 Months Ended			0 Months Ended
	Oct. 24, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 16, 2014	Dec. 17, 2013	Jul. 23, 2014	Jan. 09, 2014	Jun. 20, 2014	Sep. 23, 2013
Stockholders Equity Disclosures [Line Items]
Common stock and preferred stock, shares authorized		1,000,000,000
Common stock, shares authorized		900,000,000
Common stock, par value		$ 0.01
Preferred stock, shares authorized		100,000,000
10 to 1 reverse stock split ratio	0.10
Payments for repurchase of preferred stock		$ 0	$ 37,392,000	$ 356,000
Dividends paid on preferred stock redeemed		0	11,567,839	103,436
2.5 to one effective reverse stock split	0.40
Payments of stock issuance costs		10,041,959	11,591,773	83,739
Proceeds from issuance of common stock		190,222,034	142,105,266	4,062,647
Offering of Debt and Equity Amount Authorized									600,000,000
Other offering costs		10,041,959	11,591,773	48,752
Common Class A
Stockholders Equity Disclosures [Line Items]
Common stock, shares authorized		889,500,000	889,500,000
Common stock, par value		$ 0.01	$ 0.01
Common Stock Value, Public Offering										172,500,000
Issuance of stock (in shares)					12,500,000	10,500,000
Shares Issued, Price Per Share					$ 11.75
Proceeds from issuance of common stock					139,900,000
Preferred Stock
Stockholders Equity Disclosures [Line Items]
Payments of Ordinary Dividends and Repurchase of Preferred Stock and Preference Stock						49,000,000
Over-Allotment Option | Common Class A
Stockholders Equity Disclosures [Line Items]
Issuance of stock (in shares)							1,900,000	1,600,000
Payments of stock issuance costs								1,500,000
Proceeds from issuance of common stock							21,000,000	19,800,000
Underwriter Discounts and Commissions | Common Class A
Stockholders Equity Disclosures [Line Items]
Payments of stock issuance costs					7,000,000
Underwriter Discounts and Commissions | Over-Allotment Option | Common Class A
Stockholders Equity Disclosures [Line Items]
Payments of stock issuance costs							1,000,000
Underwriter Discounts and Commissions | IPO | Common Class A
Stockholders Equity Disclosures [Line Items]
Payments of stock issuance costs						9,900,000
Direct IPO Costs | IPO | Common Class A
Stockholders Equity Disclosures [Line Items]
Payments of stock issuance costs						1,600,000
Multi-Draw Term Facility | Amended CoBank Loan
Stockholders Equity Disclosures [Line Items]
Repayments of long-term debt						80,200,000		18,160,000
Multi-Draw and Term Loan | Amended CoBank Loan
Stockholders Equity Disclosures [Line Items]
Repayments of long-term debt					$ 118,500,000