Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED BALANCE SHEETS (Parenthetical)

v2.4.1.9
CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Convertible preferred stock issued 0us-gaap_PreferredStockSharesIssued 0us-gaap_PreferredStockSharesIssued
Common Class A [Member]    
Common stock, par value 0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common stock, shares authorized 100,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
100,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common stock, shares issued 62,046,966us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
61,584,248us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common stock, shares outstanding 38,890,533us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
40,683,984us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Treasury stock, shares 23,156,433us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
20,900,264us-gaap_TreasuryStockShares
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
Common Class B [Member]    
Common stock, par value 0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
0.01us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Common stock, shares authorized 30,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
30,000,000us-gaap_CommonStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Common stock, shares issued 12,029,375us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
12,029,375us-gaap_CommonStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Common stock, shares outstanding 12,029,375us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
12,029,375us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember