Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

Equity [Abstract]

Schedule of Stock Repurchases

Shares repurchased by the Company during 2017, 2016, and 2015 are shown in the table below.

	Total shares repurchased	Purchase price (in thousands)		Average price of shares repurchased (per share)
Year ended December 31, 2017	1,473,054	$	68,896	$	46.77
Year ended December 31, 2016	2,038,368	69,091		33.90
Year ended December 31, 2015	2,449,159	96,169		39.27