Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net cash provided by operating activities	$ 21,268	$ 8,954
Cash flows from investing activities:
Capital expenditures for property, plant and equipment	(9,600)	(13,493)
Capital expenditures for intangible assets	(756)	(83)
Purchases of assets and investments	(3,613)
Purchase of debt securities		(15,250)
Net proceeds from sale of assets		4,800
Net cash used in investing activities	(13,969)	(24,026)
Cash flows from financing activities:
Net proceeds from issuance of common shares	13,035	1,646
Changes in restricted cash		34,424
Repurchase and retirement of common shares	(43,885)
Excess income tax benefit on employee stock-based awards	105	54
Net cash (used in) provided by financing activities	(30,745)	36,124
Effect of exchange rate changes on cash	265	(1,921)
Net (decrease) increase in cash and cash equivalents	(23,181)	19,131
Cash and cash equivalents at the beginning of the period	63,663	36,815
Cash and cash equivalents at the end of the period	$ 40,482	$ 55,946