Condensed Consolidating Financial Statements (Details 4) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Sources (uses) of cash and cash equivalents
Net cash provided by (used in) operating activities	$ (26,624)	$ 50,989
Investing activities:
Capital expenditures	(30,343)	(20,105)
Acquisition, net of cash received		(11,584)
Net cash used in investing activities	(30,343)	(31,689)
Financing activities:
Proceeds from issuance of debt	15,825
Deferred acquisition payments	(6,617)
Payments of long-term debt	(1,576)	(4,084)
Net payments under other credit facilities		(3,153)
Proceeds from exercise of stock options	42	159
Debt issuance costs	(275)	(29)
Change in restricted cash		(36,497)
Net cash provided by (used in) financing activities	7,399	(43,604)
Net decrease in cash and cash equivalents	(49,568)	(24,304)
Effect of foreign currency fluctuations on cash	(458)	(584)
Cash and cash equivalents at beginning of fiscal period	210,521	152,051
Cash and cash equivalents at end of fiscal period	160,495	127,163
Parent
Sources (uses) of cash and cash equivalents
Net cash provided by (used in) operating activities	(9,510)	4,214
Investing activities:
Capital expenditures		(1)
Net cash used in investing activities		(1)
Financing activities:
Proceeds from issuance of debt	15,825
Deferred acquisition payments	(5,617)
Payments of long-term debt		(4,084)
Proceeds from exercise of stock options	42	159
Debt issuance costs	(275)
Net cash provided by (used in) financing activities	9,975	(3,925)
Net decrease in cash and cash equivalents	465	288
Cash and cash equivalents at beginning of fiscal period	7,933	6,417
Cash and cash equivalents at end of fiscal period	8,398	6,705
Guarantor Subsidiaries
Sources (uses) of cash and cash equivalents
Net cash provided by (used in) operating activities	(48,750)	32,545
Investing activities:
Capital expenditures	(9,877)	(11,505)
Acquisition, net of cash received		(11,584)
Net cash used in investing activities	(9,877)	(23,089)
Financing activities:
Deferred acquisition payments	(1,000)
Debt issuance costs		(29)
Change in restricted cash		(36,497)
Net cash provided by (used in) financing activities	(1,000)	(36,526)
Net decrease in cash and cash equivalents	(59,627)	(27,070)
Cash and cash equivalents at beginning of fiscal period	178,205	119,326
Cash and cash equivalents at end of fiscal period	118,578	92,256
Non-Guarantor Subsidiaries
Sources (uses) of cash and cash equivalents
Net cash provided by (used in) operating activities	31,636	14,230
Investing activities:
Capital expenditures	(20,466)	(8,599)
Net cash used in investing activities	(20,466)	(8,599)
Financing activities:
Payments of long-term debt	(1,576)
Net payments under other credit facilities		(3,153)
Net cash provided by (used in) financing activities	(1,576)	(3,153)
Net decrease in cash and cash equivalents	9,594	2,478
Effect of foreign currency fluctuations on cash	(458)	(584)
Cash and cash equivalents at beginning of fiscal period	24,383	26,308
Cash and cash equivalents at end of fiscal period	$ 33,519	$ 28,202