Net Income Per Share Reconciliation of Weighted Average Common Shares Outstanding (Details) - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted average shares outstanding (basic) (in shares)	169,884	175,303
Impact of common stock equivalents (in shares)	1,025	1,265
Weighted average shares outstanding (diluted) (in shares)	170,909	176,568
Basic (in dollars per share)	$ 0.33	$ 0.28
Diluted (in dollars per share)	$ 0.33	$ 0.28