Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	350,000,000	350,000,000
Common stock, issued (in shares)	105,200,000	104,400,000
Common stock, outstanding (in shares)	103,400,000	102,500,000
Treasury stock (in shares)	1,900,000	1,900,000