Summary of Significant Accounting Policies (Details 9) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Property, plant and equipment and long-lived assets
Capitalization of internal use computer software	$ 4,897	$ 9,228
Gain (loss) on disposal/write-down of property, plant and equipment	8,307	539
United Kingdom
Property, plant and equipment and long-lived assets
Gain (loss) on disposal/write-down of property, plant and equipment	$ 9,262
Number of buildings sold	2