Business Combinations, Goodwill and Intangible Assets - Summary of Company's Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	$ 181,280	$ 181,272
Accumulated Amortization	(91,951)	(80,850)
Accumulated Impairment	(5,827)	(5,827)
Total	83,502	94,595
Total intangible assets, gross carrying amount	182,180	182,172
Total intangible assets, net carrying amount	84,402	95,495
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	129,784	129,790
Accumulated Amortization	(63,261)	(56,367)
Accumulated Impairment	(5,549)	(5,549)
Total	60,974	67,874
Indefinite lived intangible assets [Abstract]
Trade names and trademarks		0
Leasehold benefits
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	2,673	2,644
Accumulated Amortization	(2,673)	(2,567)
Accumulated Impairment	0	0
Total	0	77
Developed technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	37,141	37,154
Accumulated Amortization	(17,899)	(14,653)
Accumulated Impairment	0	0
Total	19,242	22,501
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	2,045	2,045
Accumulated Amortization	(2,012)	(1,937)
Accumulated Impairment	0	0
Total	33	108
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	9,637	9,639
Accumulated Amortization	(6,106)	(5,326)
Accumulated Impairment	(278)	(278)
Total	3,253	4,035
Trade names and trademarks
Indefinite lived intangible assets [Abstract]
Trade names and trademarks	$ 900	$ 900