CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
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	196,840	257,527
Conversion of common stock units, shares	10,834	11,851
Conversion of restricted stock units, shares	65,730	119,472
Cash dividends, per share	$ 0.23	$ 0.195
Treasury stock, beginning balance, shares	23,117,554	22,943,925
Treasury stock, acquisition of shares	136,976	89,649
Treasury stock, ending balance, shares	23,254,530	23,033,574