Nature of Operations and Presentation of Condensed Consolidated Financial Statements - Summary of Error Corrections and Prior Period Adjustments (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Condensed Consolidated Income Statements and Note 12 Earnings per Share
Earnings (loss) per share - Basic	$ (0.04)	$ (0.02)	$ (0.27)	$ 0.05
Earnings (loss) per share - Diluted	$ (0.04)	$ (0.02)	$ (0.27)	$ 0.05
Condensed Consolidated Statements of Comprehensive Income (Loss)
Foreign currency translation gain (loss), net of tax	$ 8,033	$ (35,233)	$ 684	$ (14,329)
Other comprehensive income (loss), net of tax	9,931	(53,178)	7,549	(18,277)
Comprehensive income (loss)	17,201	(45,043)	16,769	175
Condensed Consolidated Statement of Shareholders' Equity
Net foreign currency translation adjustment	8,033	(35,233)	684	(14,329)
European non-controlling redeemable equity translation adjustment		2,900		2,900
Balance at June 30, 2018	371,190	369,372	371,190	369,372	$ 363,014	$ 373,265	$ 424,280	$ 445,723
Cumulative Translation Adjustment
Condensed Consolidated Statement of Shareholders' Equity
Net foreign currency translation adjustment	8,033	(35,233)	684	(14,329)
Balance at June 30, 2018	(98,606)	(89,695)	(98,606)	(89,695)	(106,639)	(99,290)	(54,462)	(75,366)
Retained Earnings
Condensed Consolidated Statement of Shareholders' Equity
Balance at June 30, 2018	$ 379,604	$ 389,465	$ 379,604	$ 389,465	$ 382,772	$ 391,037	$ 392,241	$ 393,146
As Previously Reported
Condensed Consolidated Income Statements and Note 12 Earnings per Share
Earnings (loss) per share - Basic		$ 0.09		$ 0.16
Earnings (loss) per share - Diluted		$ 0.09		$ 0.16
Condensed Consolidated Statements of Comprehensive Income (Loss)
Foreign currency translation gain (loss), net of tax		$ (38,084)		$ (17,180)
Other comprehensive income (loss), net of tax		(56,029)		(21,128)
Comprehensive income (loss)		(47,894)		(2,676)
Condensed Consolidated Statement of Shareholders' Equity
Net foreign currency translation adjustment				(17,180)
European non-controlling redeemable equity translation adjustment				2,851
Balance at June 30, 2018		369,372		369,372
As Previously Reported | Cumulative Translation Adjustment
Condensed Consolidated Statement of Shareholders' Equity
Net foreign currency translation adjustment				(17,180)
Balance at June 30, 2018		(92,546)		(92,546)
As Previously Reported | Retained Earnings
Condensed Consolidated Statement of Shareholders' Equity
European non-controlling redeemable equity translation adjustment				2,851
Balance at June 30, 2018		$ 392,316		$ 392,316
Adjustment
Condensed Consolidated Income Statements and Note 12 Earnings per Share
Earnings (loss) per share - Basic		$ (0.11)		$ (0.11)
Earnings (loss) per share - Diluted		$ (0.11)		$ (0.11)
Condensed Consolidated Statements of Comprehensive Income (Loss)
Foreign currency translation gain (loss), net of tax		$ 2,851		$ 2,851
Other comprehensive income (loss), net of tax		2,851		2,851
Comprehensive income (loss)		2,851		2,851
Condensed Consolidated Statement of Shareholders' Equity
Net foreign currency translation adjustment				2,851
European non-controlling redeemable equity translation adjustment				(2,851)
Adjustment | Cumulative Translation Adjustment
Condensed Consolidated Statement of Shareholders' Equity
Net foreign currency translation adjustment				2,851
Balance at June 30, 2018		2,851		2,851
Adjustment | Retained Earnings
Condensed Consolidated Statement of Shareholders' Equity
European non-controlling redeemable equity translation adjustment				(2,851)
Balance at June 30, 2018		$ (2,851)		$ (2,851)