Other Comprehensive Income (Loss) and Related Tax Effects (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Other comprehensive income, tax (expense) benefit
Tax effects on foreign currency translation adjustments			$ 0	$ 0
Tax effects on unrealized gains or losses on available-for-sale securities			0	0
Cumulative foreign currency translation losses	$ (110,300,000)		(110,300,000)		$ (124,300,000)
Reclassifications out of accumulated other comprehensive loss
Gains (losses) on marketable investment securities, net	230,000	$ (3,912,000)	8,179,000	(5,516,000)
Other-than-temporary impairment loss on available-for-sale securities	0	1,243,000	0	5,892,000
Other, net	645,000	2,115,000	5,900,000	(4,078,000)
Total reclassifications, net of tax and noncontrolling interests	(10,000)	1,234,000	(5,584,000)	7,752,000
Reclassification out of Accumulated Other Comprehensive Loss | Recognition of realized gains on available-for-sale securities in net income
Reclassifications out of accumulated other comprehensive loss
Gains (losses) on marketable investment securities, net	(10,000)	(9,000)	(5,584,000)	(29,000)
Reclassification out of Accumulated Other Comprehensive Loss | Recognition of other-than-temporary impairment loss on available-for-sale securities in net income
Reclassifications out of accumulated other comprehensive loss
Other-than-temporary impairment loss on available-for-sale securities	0	1,243,000	0	5,892,000
Reclassification out of Accumulated Other Comprehensive Loss | Recognition of foreign currency translation losses in net income
Reclassifications out of accumulated other comprehensive loss
Other, net	$ 0	$ 0	$ 0	$ 1,889,000