Other Assets and Liabilities - Restructuring Accrual (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Reserve [Roll Forward]
Beginning balance	$ 0	$ 0
Costs incurred and expensed	10,401	10,401	$ 0	$ 0
Costs paid/settled		(4,618)
Other costs		(3,486)
Ending Balance		2,297	0
Termination Benefits
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Costs incurred and expensed	9,000	8,746
Costs paid/settled		(3,019)
Other costs	(3,000)	(3,486)
Ending Balance		2,241	0
Contract Termination Costs
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Costs incurred and expensed	$ 2,000	1,655
Costs paid/settled		(1,599)
Other costs		0
Ending Balance		$ 56	$ 0