Stock Repurchase Program (Tables)

12 Months Ended

Dec. 31, 2017

Class of Stock Disclosures [Abstract]

Stock Repurchase Program

Under the Company's stock repurchase program, the Company repurchased shares as follows:

	Year Ended December 31,
(in thousands, except per share data)	2017		2016		2015
Number of shares repurchased	2,750		3,700		3,833
Average price paid per share	$	122.20	$	90.90	$	88.16
Total cost	$	336,042	$	336,335	$	337,910