Consolidated Statement Of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Issuance of common stock (in shares)	274,177	239,854	395,274
Issuance of deferred stock units (in shares)		63,677	4,784
Repurchases of common stock (in shares)	402,570
Special cash dividend, per share	$ 2.35	$ 2.05	$ 1.40