XML 34 R3.htm IDEA: XBRL DOCUMENT v3.3.1.900
CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Dec. 31, 2015
Dec. 31, 2014
Stockholders' equity:    
Common stock, par value (in dollars per share) $ 0.001 $ 0.001
Common stock, shares authorized (in shares) 300,000,000 300,000,000
Common stock, shares issued (in shares) 120,351,480 118,442,726
Common stock, shares outstanding (in shares) 120,351,480 118,442,726
Convertible Senior Notes [Member] | 1 Percent Convertible Senior Notes [Member]    
LIABILITIES AND STOCKHOLDERS' EQUITY    
Interest rate on convertible senior notes 1.00% 1.00%
Convertible Senior Notes [Member] | 2 3/4 Percent Convertible Senior Notes [Member]    
LIABILITIES AND STOCKHOLDERS' EQUITY    
Interest rate on convertible senior notes 2.75% 2.75%