Share Repurchase Program (Tables)

6 Months Ended

Jun. 30, 2014

Proceeds from (Repurchase of) Equity [Abstract]

Schedule of shares repurchased

	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2014		2013		2014		2013
Shares repurchased	1,873		2,546		2,022		5,013
Average price per share	$	148.21	$	107.61	$	148.21	$	100.10
Total investment	$	277,561	$	273,946	$	299,625	$	501,838