Ownership, Description of Business, and Summary of Significant Accounting Policies - Reconciliation of Shares Used in Calculating Earnings Per Basic and Diluted Shares (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Weighted average common shares outstanding-basic (in shares)	28,313	25,972	25,713
Dilutive effect of stock-based awards (in shares)	259	255	196
Dilutive effect of convertible and exchangeable senior notes (in shares)	0	178	0
Weighted average common shares outstanding-diluted (in shares)	28,572	26,405	25,909