Stockholders' Equity (Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended
		Jun. 30, 2015	Jun. 30, 2014
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at March 31, 2015		$ 2,151,586
Other comprehensive income (loss) before reclassifications		1,810
Amounts reclassified from AOCI	[1]	129
Tax effect of other comprehensive income items		(48)	$ (48)
Other comprehensive income (loss), net of tax		1,891	$ 2,656
Balance at June 30, 2015		2,122,088
Accumulated Other Comprehensive Income [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at March 31, 2015		(14,853)
Other comprehensive income (loss), net of tax		1,891
Balance at June 30, 2015		(12,962)
Foreign Currency Translation Adjustments [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at March 31, 2015		(14,690)
Other comprehensive income (loss) before reclassifications		1,810
Amounts reclassified from AOCI		0
Tax effect of other comprehensive income items		0
Other comprehensive income (loss), net of tax		1,810
Balance at June 30, 2015		(12,880)
Treasury Rate Lock Agreement [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at March 31, 2015		(163)
Other comprehensive income (loss) before reclassifications		0
Amounts reclassified from AOCI	[1]	129
Tax effect of other comprehensive income items		(48)
Other comprehensive income (loss), net of tax		81
Balance at June 30, 2015		$ (82)

[1] The reclassifications out of AOCI were associated with a loss on a treasury rate lock agreement from July 2010 related to the issuance of the Company’s 2015 Notes, which is being reclassified into earnings (interest expense) over the term of the 2015 Notes. The effects on the respective line items of the consolidated statements of earnings impacted by the reclassifications were not material for the three months ended June 30, 2015 and 2014.