Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 219,299	$ 255,872	$ 265,021
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	57,237	56,337	51,814
Amortization of debt costs	6,421	1,729	2,507
Stock-based compensation	6,280	5,857	7,835
Loss on debt refinancing	0	0	5,712
Long-lived asset impairments	28,333	0	0
Gain on sale of company-owned stores to franchisees	(7,580)	(9,940)	(2,677)
Deferred income tax expense	450	(6,418)	(1,778)
Reversal of contingent purchase price liability	0	(4,438)	(859)
Decrease (increase) in receivables	422	9,766	(13,802)
Decrease (increase) in inventory	5,381	(24,089)	(54,435)
Decrease in prepaid and other current assets	776	2,260	2,548
Increase (decrease) in accounts payable	22,375	(8,978)	6,628
Increase (decrease) in deferred revenue and accrued liabilities	9,841	12,497	(27,907)
Other operating activities	5,298	13,330	(1,161)
Net cash provided by operating activities	354,533	303,785	239,446
Cash flows from investing activities:
Capital expenditures	(45,827)	(70,455)	(50,247)
Cash paid for acquisitions (net of cash acquired)	0	(6,402)	(27,562)
Other investing activities	178	1,370	(465)
Net cash used in investing activities	(45,649)	(75,487)	(78,274)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	0	0	249,552
Proceeds from issuance of convertible senior notes	287,500	0	0
Revolving credit facility borrowings	43,000	0	0
Payments on long-term debt	(169,060)	(5,443)	(3,379)
Debt issuance costs	(8,225)	0	(2,397)
Proceeds from exercise of stock options	1,744	22,170	14,588
Excess tax benefits from stock-based compensation	604	3,743	15,369
Minimum tax withholding requirements	(574)	(762)	(1,327)
Cash paid for treasury stock	(479,799)	(283,226)	(309,255)
Dividends paid to shareholders	(59,648)	(57,491)	(57,437)
Net cash used in financing activities	(384,458)	(321,009)	(94,286)
Effect of exchange rate changes on cash and cash equivalents	(1,798)	328	790
Net (decrease) increase in cash and cash equivalents	(77,372)	(92,383)	67,676
Beginning balance, cash and cash equivalents	133,834	226,217	158,541
Ending balance, cash and cash equivalents	56,462	133,834	226,217
Cash paid during the period for:
Income taxes	121,006	125,088	143,573
Interest	42,911	48,940	40,696
Non-cash investing activities:
Capital expenditures in current liabilities	$ 6,018	$ 4,182	$ 2,489