Consolidated Statements of Equity - USD ($)	Total	Preferred stock	Common stock	Common stock Common Class A	Common stock Common Class A Common Class B-1	Common stock Common Class A Preferred stock converted	Common stock Class B-1 Common Stock	Additional paid-in capital	Other Additional paid in capital	Other Additional paid in capital Employee stock notes	Retained earnings	Accumulated other comprehensive income (loss)	Foreign currency adjustments	Unrealized (loss) gain on interest rate hedges	Net actuarial pension (loss) gain
Balance at beginning of period at Dec. 31, 2016		$ 0		$ 178,000			$ 2,000		$ 37,205,000	$ (843,000)	$ 221,146,000		$ (197,182,000)
Balance at beginning of period, shares at Dec. 31, 2016		0		17,894,393			177,221
Increase (Decrease) in Stockholders' Equity
Shares issued for exercise/vesting of share-based compensation awards				$ 21,000					1,008,000
Shares issued for exercise/vesting of share-based compensation awards, shares				2,047,668
Shares repurchased									(183,000)
Shares repurchased, shares				(2,266)
Shares issued upon conversion					$ 3,000	$ 642,000	$ (2,000)		150,901,000
Shares issued upon conversion, shares					309,404	64,211,172	(177,221)
Shares surrendered for tax obligations for employee share-based transactions				$ (7,000)					(25,897,000)
Shares surrendered for tax obligations for employee share-based transactions, shares				(742,615)
Shares issued in initial public offering				$ 223,000					480,306,000
Shares issued in initial public offering, shares				22,272,727
Costs associated with initial public offering									(7,923,000)
Distributions/ net issuances										182,000
Amortization of share-based compensation									17,910,000
Net income	$ 8,122,000										8,122,000
Foreign currency adjustments	88,788,000												88,788,000
Unrealized gain on interest rate hedges	4,486,000													$ 4,486,000
Net actuarial pension gain	9,415,000														$ 9,415,000
Balance at end of period at Dec. 31, 2017	789,136,000	$ 0	$ 1,060,000	$ 1,060,000			$ 0	$ 652,666,000	653,327,000	(661,000)	229,903,000	$ (94,493,000)	(94,493,000)
Balance at period end, shares at Dec. 31, 2017		0		105,990,483			0
Increase (Decrease) in Stockholders' Equity
Shares issued for exercise/vesting of share-based compensation awards				$ 9,000					192,000
Shares issued for exercise/vesting of share-based compensation awards, shares				907,068
Shares repurchased			$ (125,000,000.0)	$ (53,000)							(124,977,000)
Shares repurchased, shares			(5,287,964)
Shares surrendered for tax obligations for employee share-based transactions				$ (3,000)					(8,887,000)
Shares surrendered for tax obligations for employee share-based transactions, shares				(298,725)
Distributions/ net issuances										13,000
Amortization of share-based compensation									14,609,000
Net income	141,907,000										141,907,000
Foreign currency adjustments	(65,185,000)												(65,185,000)
Unrealized gain on interest rate hedges	2,636,000													2,636,000
Net actuarial pension gain	12,237,000														12,237,000
Balance at end of period at Dec. 31, 2018	761,634,000	$ 0	$ 1,013,000	$ 1,013,000			$ 0	658,593,000	659,241,000	(648,000)	246,833,000	(144,805,000)	(144,805,000)
Balance at period end, shares at Dec. 31, 2018		0		101,310,862			0
Increase (Decrease) in Stockholders' Equity
Shares issued for exercise/vesting of share-based compensation awards				$ 7,000					1,970,000
Shares issued for exercise/vesting of share-based compensation awards, shares				645,957
Shares repurchased			$ (20,000,000.0)	$ (12,000)							(19,982,000)
Shares repurchased, shares			(1,192,419)
Shares surrendered for tax obligations for employee share-based transactions				$ (1,000)					(1,956,000)
Shares surrendered for tax obligations for employee share-based transactions, shares				(96,397)
Distributions/ net issuances										(25,000)
Amortization of share-based compensation									13,190,000
Net income	62,971,000										62,971,000
Foreign currency adjustments	(15,335,000)												$ (15,335,000)
Unrealized gain on interest rate hedges	6,173,000													$ 6,173,000
Net actuarial pension gain	2,692,000														$ 2,692,000
Balance at end of period at Dec. 31, 2019	$ 812,087,000		$ 1,007,000	$ 1,007,000			$ 0	$ 671,772,000	$ 672,445,000	$ (673,000)	$ 290,583,000	$ (151,275,000)
Balance at period end, shares at Dec. 31, 2019				100,668,003			0