Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014		Dec. 31, 2013
Stockholders' equity:
Preferred stock, par value	$ 0.001		$ 0.001
Preferred stock, shares authorized	5,000,000		5,000,000
Preferred stock, shares issued	0		0
Common stock, par value	$ 0.004	[1]	$ 0.004	[1]
Common stock, shares authorized	100,000,000	[1]	100,000,000	[1]
Common stock, shares issued	54,041,829	[1]	55,067,031	[1]
Common stock, shares outstanding	54,041,829	[1]	55,067,031	[1]

[1] Reflects three-for-two stock split effective July 16, 2014