Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (Unaudited) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Dividend declared (in dollars per share)	$ 0.4050	$ 0.3700	$ 1.1800	$ 1.0650
Deferred compensation plan held Rabbi Trust (shares)	94,923	96,622	94,923	96,622	97,053	90,961
Preferred Stock, Shares Authorized	2,000,000		2,000,000		2,000,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01		$ 0.01
Shares issued under the performance incentive plan withheld for employee taxes (shares)			7,635	16,918