Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 5,836	$ 7,570	$ 7,290
Charged to Income	3,401	2,019	1,799
Charged to Equity	0	0	0
Acquisition of Business	0	0	0
Deductions	1,128	3,753	1,519
Balance at End of Year	8,109	5,836	7,570
Tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	22,620	30,102	20,228
Charged to Income	13,178	456	20,536
Charged to Equity	(6,337)	0	(2,828)
Acquisition of Business	0	0	(1,057)
Deductions	2,191	7,938	6,777
Balance at End of Year	$ 27,270	$ 22,620	$ 30,102