Goodwill and Other Intangible Assets - Summary of gross carrying amounts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Other intangible assets
Gross carrying amount	$ 248,171	$ 119,501	$ 248,171	$ 119,501	$ 119,501
Accumulated amortization	(77,260)	(63,150)	(77,260)	(63,150)	(69,685)
Net carrying amount	170,911	56,351	170,911	56,351	49,816
Amortization expense	4,665	3,268	7,672	6,549
Estimated amortization expense for other intangibles for each of the next five quarters
September 30, 2020	9,000		9,000
December 31, 2020	8,641		8,641
March 31, 2021	8,377		8,377
June 30, 2021	8,174		8,174
September 30, 2021	7,791		7,791
Thereafter	128,928		128,928
Net carrying amount	$ 170,911	$ 56,351	$ 170,911	$ 56,351	$ 49,816
Minimum
Other intangible assets
Estimated useful lives			2 years
Maximum
Other intangible assets
Estimated useful lives			15 years