CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Consolidated Statements of Changes in Shareholders' Equity [Abstract]
Common stock, par value beginning balance	$ 0.001	$ 0.001
Common stock, par value ending balance	$ 0.001	$ 0.001
Options exercised, shares	766,716	297,592
Conversion of common stock units, shares	11,851	15,084
Conversion of restricted stock units, shares	146,407	91,327
Cash dividends, per share	$ 0.585	$ 0.39
Treasury stock, beginning balance, shares	22,943,925	22,028,030
Treasury stock, acquisition of shares	173,629	801,086
Treasury stock, ending balance, shares	23,117,554	22,829,116