Segment Information, Geographic operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 170,893	$ 172,693	$ 335,403	$ 343,502
Long-lived assets	986,447		986,447		1,010,368
United States [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	101,161	104,156	197,282	203,473
Long-lived assets	782,696		782,696		785,403
Austria [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	190,843		190,843		210,755
Europe and Africa [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	42,074	40,251	83,321	82,370
Other international operations [Member] | Reportable Geographical Components [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	27,658	28,286	54,800	57,659
Long-lived assets	$ 12,908		$ 12,908		$ 14,210