Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Net income (loss)	$ (14,447)	$ (5,820)	$ (13,096)	$ (35,140)	$ (25,251)	$ (14,257)	$ (24,920)	$ (17,754)	$ (68,503)	$ (82,182)	$ 6,692
Other comprehensive income (loss):
Amounts reclassified out of OCI									10,490	(4,326)
Other comprehensive income (loss)									10,490	(4,326)	(10,535)
Total comprehensive loss									(58,013)	(86,508)	(3,843)
Foreign currency translation gains (losses), net of tax
Other comprehensive income (loss):
Amounts reclassified out of OCI									9,797	(4,569)	(8,969)
Defined benefit pension plans, net of tax impact
Other comprehensive income (loss):
Amounts reclassified out of OCI									276	420	(1,449)
Defined benefit post-retirement plan adjustments
Other comprehensive income (loss):
Amounts reclassified out of OCI									(354)	(177)	(117)
Equity interest in investee's other comprehensive loss
Other comprehensive income (loss):
Amounts reclassified out of OCI									$ 771	$ 0	$ 0