Share Repurchase Program (Tables)

3 Months Ended

Mar. 31, 2017

Proceeds from (Repurchase of) Equity [Abstract]

Schedule of shares repurchased

	For the Three Months Ended   March 31,
	2017		2016
Shares repurchased	1,829		1,231
Average price per share	$	268.09	$	254.02
Total investment	$	490,312	$	312,637