Leases - Maturities of lease liabilities (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 31, 2019
Finance Leases
2020 (excluding the three months ended March 28, 2020)	$ 4,339
2021	5,413
2022	5,062
2024	4,386
2023	3,109
Thereafter	11,223
Total lease payments	33,532
Less imputed interest	2,655
Present value, Total	30,877	$ 30,049
Operating Leases
2020 (excluding the three months ended March 28, 2020)	89,915
2021	98,707
2022	71,624
2023	43,215
2024	26,043
Thereafter	42,024
Total lease payments	371,528
Less imputed interest	26,025
Present value, Total	345,503	$ 330,100
Total
2020 (excluding the three months ended March 28, 2020)	94,254
2021	104,120
2022	76,686
2023	47,601
2024	29,152
Thereafter	53,247
Total lease payments	$ 405,060