Consolidated Statements of Stockholders' Equity (Deficit) (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
weighted average price per treasury share withheld for taxes (per share)	$ 46.83	$ 31.46	$ 14.97