Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Common stock, authorized (in shares)	100,000,000	100,000,000	100,000,000
Common stock, shares issued (in shares)	44,133,304	45,378,785	46,667,820
Common stock, outstanding (in shares)	44,133,304	45,378,785	46,667,820