Commitments and Contingencies - Leases (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016 USD ($) ft²	Dec. 31, 2016 USD ($) ft² building	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2017 USD ($)	Dec. 30, 2016 USD ($)
Operating Leases [Abstract]
Facility Purchase Price						$ 720,000
Commitments under operating leases [Abstract]
2017	$ 9,884	$ 9,884
2018	5,685	5,685
2019	5,090	5,090
2020	4,283	4,283
2021	3,993	3,993
Thereafter	22,336	22,336
Total	$ 51,271	51,271
Rent expense under operating leases [Abstract]
Rent expense under operating leases		$ 16,713	$ 15,202	$ 14,312
Tarrytown lease [Abstract]
Net Rentable Area | ft²	300,000	300,000
Payment towards purchase price	$ 57,000	$ 57,000
Capital Leases, Future Minimum Payments Due	$ 448,494	448,494
Intended Facility Financing						$ 720,000
Initial term of lease	5 years
Facilities
Commitments under operating leases [Abstract]
2017	$ 4,728	4,728
2018	4,860	4,860
2019	4,817	4,817
2020	4,271	4,271
2021	3,982	3,982
Thereafter	22,336	22,336
Total	44,994	44,994
Rent expense under operating leases [Abstract]
Rent expense under operating leases		15,861	14,659	13,360
Equipment
Commitments under operating leases [Abstract]
2017	5,156	5,156
2018	825	825
2019	273	273
2020	12	12
2021	11	11
Thereafter	0	0
Total	$ 6,277	6,277
Rent expense under operating leases [Abstract]
Rent expense under operating leases		$ 852	$ 543	$ 952
Facilities Building D and E
Operating Leases [Abstract]
Number of new buildings leased | building		2
Subsequent Event [Member]
Tarrytown lease [Abstract]
Expected reimbursement of payment made					$ 57,000