Capital Stock - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 26, 2021	May 27, 2020	Nov. 30, 2018
Equity, Class of Treasury Stock [Line Items]
Treasury stock, common (in shares)	16,781,150	16,958,418	15,530,952
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)	153,151	381,041	362,190
Treasury shares purchased		$ 19,031,000
Treasury stock issued during period (in shares)	330,419	1,491,408	197,742
Number of shares called by each right (in shares)					1
Series D Junior Participating Preferred Stock
Equity, Class of Treasury Stock [Line Items]
Number of shares called by each right (in shares)					0.001
Temporary equity, par value (in dollars per share)					$ 0.01
Purchase price (in dollars per share)					$ 12.00
Percentage threshold where the Rights become exercisable for two times the purchase price					10.00%
Value of rights as percentage of purchase price					200.00%
Convertible Notes
Equity, Class of Treasury Stock [Line Items]
Face amount repurchased	$ 33,100,000	$ 0	$ 0
Cost of repurchase	$ 29,100,000
Convertible Notes | Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Face amount repurchased				$ 13,000,000.0
Cost of repurchase				$ 12,800,000
Share repurchase program
Equity, Class of Treasury Stock [Line Items]
Treasury stock, shares, acquired (in shares)	0	2,537,833	0
Treasury shares purchased		$ 19,000,000.0
Stock repurchase program, authorized amount						$ 100,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 51,900,000
Restricted Stock
Equity, Class of Treasury Stock [Line Items]
Treasury shares purchased	$ 300,000	$ 2,700,000	$ 3,900,000