Condensed consolidating guarantor financial information - Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 303,896	$ 357,161
Accounts receivable, net	382,142	366,286
Accounts receivable from consolidated subsidiaries	0	0
Inventories, net	461,320	427,778
Prepaid expenses and other current assets	78,477	72,481
Prepaid taxes	19,306	12,463
Total current assets	1,245,141	1,236,169
Property, plant and equipment, net	425,475	432,766
Operating lease assets	107,543
Goodwill	2,250,219	2,246,579
Intangible assets, net	2,242,267	2,325,052
Investments in affiliates	0	0
Deferred tax assets	3,056	2,446
Notes receivable and other amounts due from consolidated subsidiaries	0	0
Other assets	40,709	34,979
Total assets	6,314,410	6,277,991
Current liabilities
Current borrowings	50,000	86,625
Accounts payable	108,059	106,709
Accounts payable to consolidated subsidiaries	0	0
Accrued expenses	87,698	97,551
Current portion of contingent consideration	119,706	136,877
Payroll and benefit-related liabilities	88,888	104,670
Accrued interest	6,009	6,031
Income taxes payable	4,448	5,943
Other current liabilities	29,084	38,050
Total current liabilities	493,892	582,456
Long-term borrowings	2,081,372	2,072,200
Deferred tax liabilities	604,856	608,221
Pension and postretirement benefit liabilities	86,149	92,914
Noncurrent liability for uncertain tax positions	11,029	10,718
Notes payable and other amounts due to consolidated subsidiaries	0	0
Noncurrent contingent consideration	71,965	167,370
Noncurrent operating lease liabilities	96,502
Other liabilities	203,801	204,134
Total liabilities	3,649,566	3,738,013
Total shareholders' equity	2,664,844	2,539,978
Total liabilities and shareholders' equity	6,314,410	6,277,991
Eliminations
Current assets
Cash and cash equivalents	0	0
Accounts receivable, net	5,242	5,334
Accounts receivable from consolidated subsidiaries	(793,894)	(1,520,176)
Inventories, net	(38,044)	(30,954)
Prepaid expenses and other current assets	4,113	4,113
Prepaid taxes	0	0
Total current assets	(822,583)	(1,541,683)
Property, plant and equipment, net	0	0
Operating lease assets	0
Goodwill	0	0
Intangible assets, net	0	0
Investments in affiliates	(8,684,236)	(8,447,929)
Deferred tax assets	(16,927)	(2,376)
Notes receivable and other amounts due from consolidated subsidiaries	(5,372,502)	(5,698,794)
Other assets	0	0
Total assets	(14,896,248)	(15,690,782)
Current liabilities
Current borrowings	0	0
Accounts payable	0	0
Accounts payable to consolidated subsidiaries	(793,894)	(1,520,176)
Accrued expenses	0	0
Current portion of contingent consideration	0	0
Payroll and benefit-related liabilities	0	0
Accrued interest	0	0
Income taxes payable	(1,233)	0
Other current liabilities	0	0
Total current liabilities	(795,127)	(1,520,176)
Long-term borrowings	0	0
Deferred tax liabilities	(16,927)	(2,376)
Pension and postretirement benefit liabilities	0	0
Noncurrent liability for uncertain tax positions	0	0
Notes payable and other amounts due to consolidated subsidiaries	(5,372,502)	(5,698,794)
Noncurrent contingent consideration	0	0
Noncurrent operating lease liabilities	0
Other liabilities	0
Total liabilities	(6,184,556)	(7,221,346)
Total shareholders' equity	(8,711,692)	(8,469,436)
Total liabilities and shareholders' equity	(14,896,248)	(15,690,782)
Parent Company
Current assets
Cash and cash equivalents	29,891	49,523
Accounts receivable, net	1,779	5,885
Accounts receivable from consolidated subsidiaries	32,698	32,036
Inventories, net	0	0
Prepaid expenses and other current assets	36,874	30,458
Prepaid taxes	11,489	7,029
Total current assets	112,731	124,931
Property, plant and equipment, net	3,098	3,385
Operating lease assets	13,912
Goodwill	0	0
Intangible assets, net	80	90
Investments in affiliates	5,632,043	5,984,566
Deferred tax assets	14,543	0
Notes receivable and other amounts due from consolidated subsidiaries	1,892,369	2,337,737
Other assets	19,039	17,180
Total assets	7,687,815	8,467,889
Current liabilities
Current borrowings	0	36,625
Accounts payable	3,972	3,448
Accounts payable to consolidated subsidiaries	259,906	1,058,008
Accrued expenses	6,376	5,659
Current portion of contingent consideration	0	0
Payroll and benefit-related liabilities	16,365	17,156
Accrued interest	5,978	5,995
Income taxes payable	0	0
Other current liabilities	3,988	843
Total current liabilities	296,585	1,127,734
Long-term borrowings	2,081,372	2,072,200
Deferred tax liabilities	0	87,671
Pension and postretirement benefit liabilities	43,250	49,290
Noncurrent liability for uncertain tax positions	1,042	801
Notes payable and other amounts due to consolidated subsidiaries	2,458,281	2,451,784
Noncurrent contingent consideration	0	0
Noncurrent operating lease liabilities	11,421
Other liabilities	131,020	138,431
Total liabilities	5,022,971	5,927,911
Total shareholders' equity	2,664,844	2,539,978
Total liabilities and shareholders' equity	7,687,815	8,467,889
Guarantor Subsidiaries
Current assets
Cash and cash equivalents	3,540	1,701
Accounts receivable, net	62,569	54,013
Accounts receivable from consolidated subsidiaries	353,336	1,122,107
Inventories, net	276,761	266,073
Prepaid expenses and other current assets	9,477	9,673
Prepaid taxes	0	0
Total current assets	705,683	1,453,567
Property, plant and equipment, net	239,415	253,037
Operating lease assets	59,711
Goodwill	1,255,536	1,254,848
Intangible assets, net	1,235,058	1,277,462
Investments in affiliates	2,127,743	1,625,464
Deferred tax assets	0	0
Notes receivable and other amounts due from consolidated subsidiaries	3,192,420	3,347,815
Other assets	11,802	5,776
Total assets	8,827,368	9,217,969
Current liabilities
Current borrowings	0	0
Accounts payable	62,664	62,764
Accounts payable to consolidated subsidiaries	328,596	292,093
Accrued expenses	33,982	41,873
Current portion of contingent consideration	112,329	106,514
Payroll and benefit-related liabilities	31,763	44,982
Accrued interest	0	0
Income taxes payable	0	0
Other current liabilities	13,561	34,916
Total current liabilities	582,895	583,142
Long-term borrowings	0	0
Deferred tax liabilities	354,208	257,522
Pension and postretirement benefit liabilities	26,800	27,454
Noncurrent liability for uncertain tax positions	7,329	7,212
Notes payable and other amounts due to consolidated subsidiaries	1,800,913	2,222,580
Noncurrent contingent consideration	42,647	131,563
Noncurrent operating lease liabilities	59,065
Other liabilities	9,341	8,204
Total liabilities	2,883,198	3,237,677
Total shareholders' equity	5,944,170	5,980,292
Total liabilities and shareholders' equity	8,827,368	9,217,969
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	270,465	305,937
Accounts receivable, net	312,552	301,054
Accounts receivable from consolidated subsidiaries	407,860	366,033
Inventories, net	222,603	192,659
Prepaid expenses and other current assets	28,013	28,237
Prepaid taxes	7,817	5,434
Total current assets	1,249,310	1,199,354
Property, plant and equipment, net	182,962	176,344
Operating lease assets	33,920
Goodwill	994,683	991,731
Intangible assets, net	1,007,129	1,047,500
Investments in affiliates	924,450	837,899
Deferred tax assets	5,440	4,822
Notes receivable and other amounts due from consolidated subsidiaries	287,713	13,242
Other assets	9,868	12,023
Total assets	4,695,475	4,282,915
Current liabilities
Current borrowings	50,000	50,000
Accounts payable	41,423	40,497
Accounts payable to consolidated subsidiaries	205,392	170,075
Accrued expenses	47,340	50,019
Current portion of contingent consideration	7,377	30,363
Payroll and benefit-related liabilities	40,760	42,532
Accrued interest	31	36
Income taxes payable	5,681	5,943
Other current liabilities	11,535	2,291
Total current liabilities	409,539	391,756
Long-term borrowings	0	0
Deferred tax liabilities	267,575	265,404
Pension and postretirement benefit liabilities	16,099	16,170
Noncurrent liability for uncertain tax positions	2,658	2,705
Notes payable and other amounts due to consolidated subsidiaries	1,113,308	1,024,430
Noncurrent contingent consideration	29,318	35,807
Noncurrent operating lease liabilities	26,016
Other liabilities	63,440	57,499
Total liabilities	1,927,953	1,793,771
Total shareholders' equity	2,767,522	2,489,144
Total liabilities and shareholders' equity	$ 4,695,475	$ 4,282,915