Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 segment	Jun. 30, 2013	Dec. 31, 2013
Segment Information
Number of reportable segments			2
Segment Information
Total revenues from external customers	$ 687,108	$ 643,976	$ 1,353,396	$ 1,278,311
Operating income	19,264	51,510	86,152	99,761
Total assets	2,538,644	2,341,274	2,538,644	2,341,274	2,556,588
Asset impairment charges	52,564	0	52,564	0
Early Development
Segment Information
Total revenues from external customers	231,198	214,582	449,422	421,858
Operating income	(22,424)	21,882	(2,948)	38,439
Total assets	1,083,416	1,123,348	1,083,416	1,123,348
Restructuring costs	651	2,342	2,281	5,895
Asset impairment charges	52,564		52,564
Late-Stage Development
Segment Information
Total revenues from external customers	408,258	377,716	810,086	750,639
Operating income	87,051	79,500	180,103	162,449
Total assets	1,230,042	1,001,028	1,230,042	1,001,028
Restructuring costs	3,150	1,363	3,396	3,261
Other Reconciling Items
Segment Information
Total revenues from external customers	47,652	51,678	93,888	105,814
Operating income	(45,363)	(49,872)	(91,003)	(101,127)
Total assets	225,186	216,898	225,186	216,898
Restructuring costs	$ 397	$ 2,308	$ 2,658	$ 3,027