Net Income Per Share Reconciliation of Weighted Average Common Shares Outstanding (Details) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted average shares outstanding (basic) (in shares)	165,324	175,942	167,834	175,672
Impact of common stock equivalents (in shares)	802	1,186	888	1,176
Weighted average shares outstanding (diluted) (in shares)	166,126	177,128	168,722	176,848
Basic (in dollars per share)	$ 0.38	$ 0.37	$ 1.06	$ 0.86
Diluted (in dollars per share)	$ 0.37	$ 0.37	$ 1.06	$ 0.85