Shareholders' Equity (Tables)

9 Months Ended

Sep. 30, 2018

Shareholders’ Equity [Abstract]

Common Stock Repurchases

	Three months ended				Nine months ended
	September 30,				September 30,
	2018		2017		2018		2017
Shares of common stock repurchased		40		301		334		545
Total cost of common stock repurchased	$	18,885	$	102,511	$	115,300	$	207,159