Condensed Consolidating Statement of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of Condensed Consolidating Statement of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	$ 23,450	$ 14,374
Cash flows from investing activities:
Additions to property, plant and equipment	(3,342)	(9,265)
Proceeds from sale of property, plant and equipment	5,099	79
Net cash provided by (used in) investing activities	1,757	(9,186)
Cash flows from financing activities:
Cash provided by (used in) intercompany activity	0	0
Repayments of long-term debt	(3,750)	(3,750)
Dividends paid on common shares and restricted stock	(12,011)	0
Repurchases of common stock	(21,168)	(1,366)
Proceeds from issuance of common stock	14,836	5,685
Net cash provided (used in) by financing activities	(22,093)	569
Effect of exchange rate changes on cash and cash equivalents	(621)	(529)
Net increase (decrease) in cash and cash equivalents	2,493	5,228
Cash and cash equivalents at beginning of period	94,711	101,971
Cash and cash equivalents at end of period	97,204	107,199
Parent Company
Schedule of Condensed Consolidating Statement of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	13,200	35,072
Cash flows from investing activities:
Additions to property, plant and equipment	(568)	(2,372)
Proceeds from sale of property, plant and equipment	0	79
Net cash provided by (used in) investing activities	(568)	(2,293)
Cash flows from financing activities:
Cash provided by (used in) intercompany activity	13,445	(24,889)
Repayments of long-term debt	(3,750)	(3,750)
Dividends paid on common shares and restricted stock	(12,011)
Repurchases of common stock	(21,168)	(1,366)
Proceeds from issuance of common stock	14,836	5,685
Net cash provided (used in) by financing activities	(8,648)	(24,320)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	3,984	8,459
Cash and cash equivalents at beginning of period	62,836	68,887
Cash and cash equivalents at end of period	66,820	77,346
Guarantor Subsidiaries
Schedule of Condensed Consolidating Statement of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	13,877	(19,760)
Cash flows from investing activities:
Additions to property, plant and equipment	(2,577)	(6,736)
Proceeds from sale of property, plant and equipment	5,099	0
Net cash provided by (used in) investing activities	2,522	(6,736)
Cash flows from financing activities:
Cash provided by (used in) intercompany activity	(13,445)	24,889
Repayments of long-term debt	0	0
Dividends paid on common shares and restricted stock	0
Repurchases of common stock	0	0
Proceeds from issuance of common stock	0	0
Net cash provided (used in) by financing activities	(13,445)	24,889
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	2,954	(1,607)
Cash and cash equivalents at beginning of period	10,745	7,543
Cash and cash equivalents at end of period	13,699	5,936
Non-Guarantor Subsidiaries
Schedule of Condensed Consolidating Statement of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	(3,627)	(938)
Cash flows from investing activities:
Additions to property, plant and equipment	(197)	(157)
Proceeds from sale of property, plant and equipment	0	0
Net cash provided by (used in) investing activities	(197)	(157)
Cash flows from financing activities:
Cash provided by (used in) intercompany activity	0	0
Repayments of long-term debt	0	0
Dividends paid on common shares and restricted stock	0
Repurchases of common stock	0	0
Proceeds from issuance of common stock	0	0
Net cash provided (used in) by financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	(621)	(529)
Net increase (decrease) in cash and cash equivalents	(4,445)	(1,624)
Cash and cash equivalents at beginning of period	21,130	25,541
Cash and cash equivalents at end of period	16,685	23,917
Consolidating Adjustments
Schedule of Condensed Consolidating Statement of Cash Flows [Line Items]
Net cash provided by (used in) operating activities	0	0
Cash flows from investing activities:
Additions to property, plant and equipment	0	0
Proceeds from sale of property, plant and equipment	0	0
Net cash provided by (used in) investing activities	0	0
Cash flows from financing activities:
Cash provided by (used in) intercompany activity	0	0
Repayments of long-term debt	0	0
Dividends paid on common shares and restricted stock	0
Repurchases of common stock	0	0
Proceeds from issuance of common stock	0	0
Net cash provided (used in) by financing activities	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0