Capital Stock - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2018
Equity, Class of Treasury Stock [Line Items]
Treasury stock, common (in shares)	16,958,418	15,530,952	15,366,504
Preferred stock, shares authorized (in shares)	1,000,000
Preferred stock, par or stated value per share (in dollars per share)	$ 0.01
Preferred stock, shares outstanding (in shares)	0	0	0
Treasury stock, shares, acquired (in shares)	381,041	362,190	415,418
Treasury shares purchased	$ 19,031,000
Treasury stock issued during period (in shares)	1,491,408	197,742	210,964
Share repurchase program [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury stock, shares, acquired (in shares)	2,537,833
Treasury shares purchased	$ 19,000,000.0
Treasury stock issued during period (in shares)		0	0
Stock repurchase program, authorized amount	81,000,000.0			$ 100,000,000
Share repurchase program [Member] | Convertible Notes due 2021 [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount				$ 33,500,000
Restricted Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury shares purchased	$ 2,700,000	$ 3,900,000	$ 3,200,000