Operating lease liability maturities (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Lessee Disclosure [Abstract]
Operating lease liability payments, due 2019 (remaining after March 31, 2019)	$ 21,217
Operating lease liability payments, due 2020	16,384
Operating lease liability payments, due 2021	11,074
Operating lease liability payments, due 2022	5,123
Operating lease liability payments, due 2023	3,316
Operating lease liability payments, due thereafter	3,721
Total lease payments	60,835
Imputed interest	(6,339)	[1]
Total operating lease liability	$ 54,496
Weighted-average discount rate	6.60%
Operating lease not yet commenced, amount	$ 7,800
Operating lease not yet commenced, term	14 months

[1] (1) The weighted-average discount rate used to determine the operating lease liability as of March 31, 2019 was 6.6 percent.