Common Stock	12 Months Ended
Dec. 31, 2015
Equity [Abstract]
Common Stock	Note 9 - Common Stock In October 2012, we completed a follow-on offering of common stock in which we sold a total of 7,964,601 shares of our common stock and received cash proceeds of $222.1 million (which included 35,398 shares or $1.0 million sold to our CEO) from this transaction, net of underwriting discounts and offering costs. In May 2013, we completed a public offering of common stock and sold a total of 3,902,862 shares of our common stock for total cash proceeds of approximately $355.1 million (which included 487,857 shares or $45.0 million sold to our CEO), net of underwriting discounts and offering costs. We also sold 596,272 shares of our common stock to our CEO and received total cash proceeds of $55.0 million in a private placement at the public offering price. Concurrent with these equity transactions, we also issued $660.0 million principal amount of 1.50% convertible senior notes in a public offering and received total cash proceeds of approximately $648.0 million, net of underwriting discounts and offering costs (see Note 8 – Convertible Notes and Long-Term Debt Obligations). In August 2015, we completed a public offering of common stock and sold a total of 3,099,173 shares of our common stock for total cash proceeds of approximately $738.3 million (which includes 82,645 shares or $20.0 million sold to our CEO, net of underwriting discounts and offering costs.

Common Stock

12 Months Ended

Dec. 31, 2015

Note 9 - Common Stock

In October 2012, we completed a follow-on offering of common stock in which we sold a total of 7,964,601 shares of our common stock and received cash proceeds of $222.1 million (which included 35,398 shares or $1.0 million sold to our CEO) from this transaction, net of underwriting discounts and offering costs.

In May 2013, we completed a public offering of common stock and sold a total of 3,902,862 shares of our common stock for total cash proceeds of approximately $355.1 million (which included 487,857 shares or $45.0 million sold to our CEO), net of underwriting discounts and offering costs. We also sold 596,272 shares of our common stock to our CEO and received total cash proceeds of $55.0 million in a private placement at the public offering price. Concurrent with these equity transactions, we also issued $660.0 million principal amount of 1.50% convertible senior notes in a public offering and received total cash proceeds of approximately $648.0 million, net of underwriting discounts and offering costs (see Note 8 – Convertible Notes and Long-Term Debt Obligations).

In August 2015, we completed a public offering of common stock and sold a total of 3,099,173 shares of our common stock for total cash proceeds of approximately $738.3 million (which includes 82,645 shares or $20.0 million sold to our CEO, net of underwriting discounts and offering costs.