Summary of Significant Accounting Policies Antidilutive Securities Excluded from Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Number of stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		524,887		524,887
Weighted-average exercise price (in dollars per share)		$ 11.88		$ 11.88
Weighted-average shares of non-vested restricted stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		55,125		55,125
Weighted-average expense per share (dollars per share)		$ 15.52		$ 15.52
Weighted-average number of shares issuable upon conversion of debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	32,599,702	29,726,047	31,257,300	29,726,047
Weighted-average conversion price (dollars per share)	$ 18.36	$ 14.50	$ 17.30	$ 14.50