Supplemental Balance Sheet, Income Statement and Cash Flow Information (Details 5) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unrealized (gains) losses on available-for-sale securities that were reclassified from net income
Investment income (loss)	$ 2,308	$ 11,831	$ 96,577
Impairment and other charges	368,967	1,027,423	287,241
Interest expense	181,928	177,948	223,418
General and administrative expenses	324,328	500,036	479,890
Other expense (income), net	(39,172)	9,073	37,977
Total before tax	(427,535)	(604,615)	106,160
Tax expense (benefit)	98,038	(62,666)	55,181
Net income (loss)	(372,294)	(669,244)	147,162
Reclassification adjustment for (gains)/losses included in net income (loss)
Unrealized (gains) losses on available-for-sale securities that were reclassified from net income
Investment income (loss)		4,635	88,158
Impairment and other charges		6,972
Interest expense	613	614	613
General and administrative expenses	1,104	303	991
Other expense (income), net	(5,365)
Total before tax	(7,082)	(3,254)	86,554
Tax expense (benefit)	648	(552)	(2,080)
Net income (loss)	$ (6,434)	$ (3,806)	$ 84,474